I think I've figured it out: We must hire an exorcist; Anthony is possessed. 

He doesn't get upset as often as he did when I posted in February, perhaps because we have given up (to a great extent) trying to stretch him with instructions on washing his hands, et cetera.  But when he does get upset, there is essentially no course for resolution until he calms down on his own after 20-30 minutes.  If he breaks things, we just have to live with it.  Gratefully, he has not gone after the mirror in the bathroom, but we have several other items like tables and countertops, as I mentioned previously, that could certainly eventually give way. 

He is no longer afraid to come after me any more, either, which is a big concern--not because I can't defend myself, but because the level of retaliation required to subdue him is now at the stage where it would be considered physical abuse.   If I had, for instance, an unknown attacker come after me, I could feasibly resolve the situation by leaving him with serious injuries to vital areas, and a court would accept that as reasonable self-defense.  Clearly, if I send Anthony to school with bruises and possibly broken bones, there is a very real possibility that I would end up in jail.  So ours is a no-win situation.  We try to cordon him off in his room or somewhere else where he can't attack us, and live with whatever he decides to destroy.