While it should work, affectsCorpses="0" does nothing to delayed triggers it seems. There's nothing else it just doesn't work.
I've not noticed this. so if a monster is standing on a stack of corpses and you shoot a rocket fist at it (or some other spell with delayed trigger effects) it will hit multiple times for each corpse on the tile?
I think it might. In that case the fist would knock back without any negative effects. I just noticed it because one of my dots (that used triggers instead) was ignoring this and still dealing damage after the target had died.
I noticed this too. the problem goes away if you use dot instead of trigger, and it only happens after something is dead, not when a corpse is targeted.