I don’t see how wife burning could possibly be a religious issue. To me, if you burn your wife, you’re guilty of either assault or murder.
As for polygamy, I think it should be legal but that’s just me. I am against polygamy religiously but not everyone is against it as I am.
I already admit the existence of ethics independent of religion. And frankly, I don’t find your post to be very convincing either. Wife burning is obviously violating someone else’s right to live. Of course you would probably say that abortion is also violating someone else’s right to live but then we get in to the debate of when the fetus has rights and when it does not.