I don't think you need to make marriage even more unattractive. Such a law *will* be abused, and the government will be jumping with joy whenever any complaint is made, valid or not.
In this case the guy is a felon, or he is not. If he is not then he keeps all his rights. If he is then he loses some. No new laws needed.
My point was that if someone has such little self-control and good sense as to behave like this guy, then I agree that he and others like him who beat their wives and act the horse’s ass in general should not be allowed around firearms lest they really hurt someone.
Marriage is either attractive or not, depending on a person’s conception of it. I find it difficult to believe that a person would decline to get married on the basis of possibly losing his firearm rights.