I've wondered sometimes if she talked the Hat out of Ravenclaw, just like Harry did with Slytherin. Like you mentioned, part of it is our choice, and everyone has bits and pieces of each House in them. The same with MBTI, everyone uses each function, which is forgotten at times. We are dynamic, complex creatures, and when we try to force ourselves inside boxes into which we do not fit, we have to carve away pieces of ourselves to do so. That's one of the reasons why I love your description of what the Houses mean to you so much, it resonates with me terribly well. :}
Still, we all do have our strengths and weaknesses, but when one brings a variety of people together, I believe their strengths are amplified, and their weaknesses diminished - which is why I've always loved the variety of types here on the forum. I love it when people come together, work together, grow together.
*realizes she's rambling, scurries away back into the shadows*