I hope Le Pen win, she will take France out of E.U. and that's a good thing for French. I don't know if that would be a good thing for btc, but it will be for the people of France.
European Union is not the reason behind decline of France. It is because their own internal immigrant policy.
France was colonial power and always keep close ties with African and Middle Eastern colonies.
That is the reason why France is so culturally and ethnically divided. If France will leave UE it won't change anything.