The only law should be that religious dogma be illegal whenever it does not tolerate intellectual inquiry.
That is all.
As for the burka, I can see the pragmatic reasons for its prohibition. I wouldn't specifically target it, though. I'd argue that any mask that covers a particular portion of the face should not be immune to restrictions in particular activities. Furthermore, because we recognise individual freedom, I must agree that a husband should be incarcerated if he forces his wife to wear a burka (or anything that the woman would not consent to without fear being used to apply external pressure on her).
I doubt that women "want" to wear it so much as they feel that they have to, considering their specific situation (external pressure from family and religion, the latter of which depends largely on the particular interpretation of her immediate social context. That said, society is also restricted from walking around naked in public - a state that is much more natural to humans, as we are all born thus, and one which may also be a tenet of particular beliefs. It is restricted on similar grounds: people in that society agree that it's not something they wish to see in the streets.
Concerning assimilation, I've recently posed a similar question: should the immigrant be assimilated or should they be allowed to assimilate?
A false dichotomy, perhaps. Essentially, the crux of the problem seems to lie in the idea of identity and, more specifically, the synthetic existence of culture and its application towards the formation of an identity. In all cases, I see basing one's own identity on such things to stunt individual growth and limit that which one is capable of. If anything, it is what prevents us from being free agents. Culture, as a part personal identity, just encourages conformity. In this case, the French wish for conformity on their territory, but immigrants wish to conform to the norms of their home country. This creates a clash. We talk about individual freedoms, but we don't realise that this is has very little to do with individual freedom. If anything, this clash is a wonderful example of what happens when two systems wishing to establish mutually exclusive conformity norms collide. Nobody is being an individual.
That said, the choice was made to immigrate. If I invite myself to someone's house, it would not be right for me to flaunt the manner in which I do things in my own home. My instinct is to observe, understand and seek to be understood and then assert my individuality. In a way, it should become possible for an individual to respect something without conforming to it, but not conforming does not mean threaten. By being consistently different in the same way, it will gave the impression of a threat. It becomes an "us vs them". In that regard, let the French govern themselves and the Arab world govern itself. The Arab countries might feel threatened if Americans emigrated en masse and asserted "American values" blatantly. In many Arabic countries, as I understand it, it is already illegal to assert many of those values, regardless of the immigration situation.
In the end, let us recognise that both examples of cultural conformity are just ploys to control people. This is just a situation where two different systems collide.
Agapooka