Ok after hours of brainstorming here is a proposed solution to corpse humping: The immunity to corpse humping potion, call it "potion of free death" if you like (for similarity with free mind/free action). Tadaaa
Basically it's a ward, that lasts, say 30 sec, and remains active after death (might need some coding effort here). While it is in effect nobody can sit on your corpse, the ennemy can try but nothing happens. So when you see your ennemy coming (or when something 1 pixel high starts beating hard on you), just quickly pop your potion ! The guy will still kill you in 3 sec but in the end you owned him because he can't corpse hump
See the logic there ? omg I can't wait for that to be put in game !