You know what though. If France were really concerned about the loss of their culture, they could even adopt a system similar to Britain's, which I think is a good balance between church and state. On the one hand, the Queen is simultaneously the executive of government, as well as the head of the anglican church, thus effectively giving Christianity a certain recognition. yet on the other hand, individuals are free to worship as they with.
Now France hasn't got a Queen of course, but it could simply adopt Christianity as its official religion, even if it really means nothing other than to make Christians feel good. That alone might make them less paranoid about Muslims, feeling that with Christianity being official, it has some special recognition at least, so that then they could let Muslims go about their daily business without so much paranoia.