First of all, hello and thank you for your questions. I am a practicing Roman Catholic, and have been my entire life. I do not find your questions to be offensive at all: honestly, I'm just glad that you asked them instead of not and forming opinions which may have been incorrect. I'll go through and try to answer each of your questions one by one. This may not be necessary for me to say, but as a practicing Catholic, I will answer your questions from the perspective of a practicing Catholic, using Catholic theology. Also, I have not gone through the entire thread, so if I repeat something that has already been said I apologize.
WARNING! The following questions and musings may be offensive to some. It is not intended as such.
Drinking wine as if the blood and eating bread as if the flesh of Christ seems awfully cannibalistic. Why does Catholicism promote these symbolically cannibalistic rituals?
I think this is probably one of the most misunderstood aspects of Catholicism. First of all, we do not believe that the wine and the bread simply represent Christ's body and blood: we believe that they ARE His body and blood. However, the Eucharist (what we call the bread and the wine when it turns into the Body and Blood of Christ during the Mass) is more than Christ's Body and Blood: it is His Body, Blood, Soul, and Divinity. In other words, the Eucharist IS Jesus Christ, both His full humanity and His full divinity. In short, the Eucharist is God since Christ is God. So when we eat the Body of Christ and drink His Blood we believe that God Himself is coming into our bodies and souls. This is our 'daily bread' which Christ mentions in The Lord's Prayer (Our Father); it is the manna which gives us the sustenance we need in our daily lives; God Himself is our food and our drink. This is mind-boggling on many accounts, one of which is how humble God shows Himself to be. At first He came down and "took the form of a slave, being born in the likeness of men," to quote St. Paul in his letter to the Philippians, but then He goes even farther, taking the form of bread and wine, two of the simplest kinds of food and which, in order to be made, must be crushed and ground over and over again (ground wheat to make the bread, crushed grapes to make the wine). This also has connections to the Crucifixion, where Christ was literally crushed in the most brutal of fashions, ultimately (to finish the thought of St. Paul from the Philippians), humbling "himself and became obedient unto death, even death on a cross." We celebrate the Eucharist, and consume the Eucharist, to receive the spiritual nourishment that we need and to commemorate Christ's passion and death, which led to the glory of the resurrection from the dead. There's a lot more to it (I'm still constantly learning about more connections!) but does what I said make sense?
Why do people worship Jesus and thank him for everything? Won't God get pissed off that his son gets all the credit?
"I created the world and all life; all this guy did was street magic, but he gets all the love? WTF?" - This comes to mind in the form of a cartoon. I wish I could draw it. NOTE: Just sharing an amusing thought, not trying to be offensive.
An important tenant of most branches of Christianity is the belief in the Trinity. In brief, the Mystery of the Trinity states that there are three Divine Persons (Father, Son, and Holy Spirit), but they are one God. However, this does not mean that without the other two Persons of the Trinity, the third Person is not God: He is still God. The Father, in and of Himself, is fully God; the Son, in and of Himself, is fully God, and the Holy Spirit, in and of Himself, is fully God. At the same time, however, all of them together do not make some 'super-God', but are still fully God, just as they are in and of themselves. It is a very confusing dogma, and one which many of the greatest minds in the Church have tackled (St. Augustine, St. Thomas Aquinas, St. Patrick, St. Gregory Nazianzus, St. Gregory of Nyssa, and St. Basil the Great, to name a few), but it is not something which, I think, we will ever be able to fully comprehend. What comes to my mind here is an experience that St. Augustine had. If you're not familiar with St. Augustine, he was a bishop in Northern Africa who lived from the mid 4th to the early 5th centuries. He had a great philosophical education, and to this day is considered one of the greatest minds the Catholic Church has ever known. Anyway, one day, St. Augustine was walking along the beach and he came up to a young boy who was running back and forth between the ocean and a hole he had dug in the sand, emptying water from the ocean into the hole in the sand with a bucket. St. Augustine asked the boy what he was doing, and he replied that he was putting the ocean into the hole. Obviously, the little boy was never going to achieve his goal: the hole in the sand simply would not be able to hold the entire ocean! Now imagine our minds as the hole in the sand, and God as the ocean: we can run back and forth, trying to fill our minds with the knowledge of God as much as we can, but there's always going to be more for us to learn. This isn't to say that we shouldn't try and learn more about God, though: far from it! God gave us our intellects for a reason, and it would be a terrible misfortune not to use them! But we also need to be aware that God is greater than we could ever possibly imagine.
Anyway, to get back to your original question of why people worship Jesus and thank Him for everything and wouldn't the Father get pissed that He was being ignored, it goes back to what I said about the Trinity: the Father and the Son are one and the same while also being different. When someone is thanking Jesus, he is thanking God, and since the Father is also God the person is also thanking the Father. For most people (myself included), it is simply easier to relate to Jesus since, while being God, He is also human. Does this make sense?
For that matter, why were these feats viewed as miracles of God and not witchcraft of the Devil?
Some did view Christ's miracles as witchcraft of the devil. However, to quote from the Gospel of Matthew, chapter 7 verses 15-20, "Beware of false prophets, who come to you in sheep's clothing but inwardly are ravenous wolves. You will know them by their fruits. Are grapes gathered from thorns, or figs from thistles? So, every sound tree bears good fruit, but the bad tree bears evil fruit. A sound tree cannot bear evil fruit, nor can a bad tree bear good fruit. Every tree that does not bear good fruit is cut down and thrown into the fire. Thus you will know them by their fruits." What were the fruits that Christ brought wherever He went? Love, peace, mercy, justice. Such things the devil cannot provide.
Why isn't there more Jewish traditions in Christianity if Christ was Jewish? Won't God get pissed off that Christ changed all the rules?
I can only speak for Catholicism here, as I am Catholic and have not gone to many non-Catholic services, but within the Catholic tradition there are many Jewish traditions that have been carried over. The most obvious example is what Christians call the Old Testament: the Old Testament is the entirety of the Jewish Scriptures. These are still regularly used in Christian services of all kinds, and what is written in the Old Testament is conceived as being fulfilled in the New Testament by the coming of Christ. Therefore, what Jewish traditions were changed by the Christians were not just changed for the heck of it: specific traditions were changed as a fulfillment of older traditions. For example, the Sabbath day. Jews understood the Sabbath day as beginning at sundown the day before the Sabbath: Catholics can go to Mass Saturday evening and fulfill their Sunday obligation. The Sabbath day itself was moved from Saturday to Sunday, since tradition holds that Sunday was the day Christ rose from the dead, but the same principle applies to it beginning the evening before. Another tradition that has carried over is the different times for prayer during the day. Traditionally, Jews would pray in the morning, at midday, and in the evening, mainly reading the psalms and canticles from other books in the Old Testament. Catholics, Orthodox, and perhaps some denominations continue this practice in what is commonly known as the Liturgy of the Hours, which all Catholic priests and religious are required to pray everyday, and which the lay faithful are encouraged to pray. The Liturgy of the Hours, after the Mass, is the official prayer of the Catholic Church.
Was it part of God's plan to kill his son? Dick-move, don't you think? Honour thy father, but fuck your kids?
In order to understand the crucifixion, you need to understand the reason behind it. God is both perfectly just and perfectly merciful. When sin first entered the world through the free choice of Adam and Eve, they put an infinite distance between humanity and God, for in order to disobey One Who is infinite (God) one must choose to disobey infinitely (sin). Sin, by its nature, is a turning away from God. Adam and Eve, as our first parents, had the choice to either stay and follow God, or turn and follow their own designs, and they chose the latter. In doing so, they also condemned the rest of the human race to death (the ultimate effect of sin since God is the source of our life), as well as to have a tendency to turn away from God (what is known as concupiscence). This combination of effects, in short, is what is known as Original Sin. Because the Original Sin was an act against an infinite being (God) the effect that it has is infinite. Now, humans, by our nature, are finite. As such, there is nothing that we can do which would be able to restore our good standing with God since sin put us an infinite distance away from Him. BUT God did not abandon us like we did Him. Because He is perfectly just, there needed to be a just recompense for the sin, which could only be given by a human, which, because of our nature, we could not do; because He is perfectly merciful, He sent His Only-Begotten Son, Who took on a human nature, in order to bring humanity back into communion with God by means of the Cross
and Resurrection. God sent His Son out of love, and the Son, our of love for His Father and for humanity, willingly laid down His life. Again, the Father and the Son are one, the Father's will is the Son's will. Does that make sense?
Why was it acceptable that we trust someone that claims to be the son of God 2000 years ago, but nowadays we call them Schizophrenic?
People have claimed to be the son of God, or God Himself, throughout the centuries. The Caesars of the Roman Empire were considered to be gods by their subjects, with the exception of the Jews and the Christians. Side note: One of the reasons the Christians were so brutally persecuted in the first centuries of Christianity was because, while the Jews had an exemption from worshiping Caesar, when the Jews and Christians officially split and became separate religions the same exemption did not apply to Christianity. Anyway, I think it all comes back to what I said earlier about by their fruits you will know them. Christ did heal the sick, raise the dead, return sight to the blind, speech to the mute, hearing to the deaf, etc. etc. Christ was not schizophrenic: He did not have multiple personalities. Yes, He has a divine and a human nature, but He is one Divine Person. This is known as the Hypostatic Union.
Why is God wrathful and Jesus forgiving? Don't do wrong or God will smite you, but it's ok, because Jesus forgives you. That sounds like being part of a dysfunctional family where God, as the father, beats you for doing something he doesn't like; but then Jesus, as the caring 'mother', tells you that everything is ok, it's not your fault, father is just having a bad day, and you're forgiven. No wonder the crusades happened. Like a bunch of angry teenagers looking to start some shit because of the shitty childhood they had.
This goes back to the perfectly just and perfectly merciful answer I gave above about the Cross. If you need me to explain it again in this context, please let me know and I will do my best. Concerning the crusades, they were a sad part in the history of the Church, to be sure, but from my understanding they were done under a misguided sense of zeal for God, to the point of killing others for Him. This is not at all what Christianity teaches, and the Catholic Church has officially apologized for the Crusades.
NOTE: To be clear of my intentions -- my ultimate goal is not to question the existence of God or Jesus or your faith. That is irrelevant to me. I am questioning the 'logic' or rationale behind the beliefs. Even if I can somehow disprove this rationale, it does not therefore negate anyone's belief or prove/disprove whether or not God or Jesus exists; it just negates the reasons. Even if I can't prove anything, it'll make for a fun or ridiculous argument that amuses at least me.
Thanks again for being clear about your intentions. While I do not think the rationale behind Catholic beliefs can be disproved (why would I be a Catholic if I thought that? Hence why relativism doesn't make any sense to me, but that's another topic entirely), I will say that there are aspects of Catholicism which transcend reason, and hence which cannot be proved/disproved by the human intellect. Again, this is not to say that we should not be asking these questions, but simply that there is a reason why it is called the Christian/Catholic faith. I hope everything I said makes some sort of sense, and I will try to reply in a reasonable time, but please be patient with me: I'm not online very often.