Well, Your all Looking at all the Negitives of HOs why don't you look at the bright side? Lets say we have Mr. Instant Healing and Mr. Blaster or Mrs. Tanker a few HOs will work well on all of them(Damage Cap/Defesne Cap/Healing Cap).
So Maybe we can have a HO limit(Just 6 To maximize a Power)(Or Only 2 to make it fair to lower lvl people)