O-kaaay, so much fail here, it will need several answers.
First : We don't have gay marriage here. We have the PACS which is a little weaker than the actual marriage and is open to oth homosesual and heterosexual couples. Marriage is a distinct legal contact, and is only open to heterosexual couples. That said, I'd prefer if you were right on that point.
Second, "religious symbols/ clothing/ outward expression of faith in public places" is totally ok. there is some conteroversy about the burka (integral muslim veil) beut somehow I do not thing that is what bothering you. And I do not believe the butka law ever passed.
There are however some restrictions that apply in schools, since they are "laic" (by a long tradition). One of my friends was once asked to wear a smaller crucifix, and muslim girls are asked to wear a scarf rather than a veil.
And third, we are a sovereign country, asshole. Contrary to what you may think, american law does not apply outside the USA.
Darkloid_Blues :
Yes and no. We have a lot of people who are "historically" catholics (about 90% of the population). When you ask a little more in details about frenc beliefs, you find a third of agnostics, a third of atheists, and only a third of people who do believ ein a deity. Many, however, still tick the "catholic" box because they were raised catholics and they identify with the morals and ethics of the religion, not the religious dogma. This is mostly the crowd that will go to church on a friend's wedding day, maybe at christmas and not once more during the year.
French engineer