Absolutely. The argument, "Believe this or everything will go to Hell," is the weakest possible. Things are believed because they're true, not because the masses will be better governed if they trust in the divine right of kings, for example.

The law need not appear inevitable. It could be argued that a rational actor would almost always choose the law as a dispute-resolution heuristic. It's just that "almost" that worries me. As I've said before, my view of my own best interest varies depending on how much I've had to eat. It's tempting to view obedience to the law as inherent in the idea of a state, and derive much moral maundering from that postulate, as Kant does. But I think it's false to do so. There are such things as legitimate rebellions.

As to legal mutations, any organism detests mutations: so few of them are beneficial. What's needed is a method by which bad mutations are lost and good mutations are gained. It's this evolutionary role which history plays, and which we've both been admiring.