First of all, I don't see why with the plethora of OGCD heals, with all of the regens, and shields that we have on hand- it should hardly make a healer pause if someone takes occasional avoidable damage.
Secondly, I haven't seen stress on perfect play, on the contrary the discussion has been on all levels of play. if it was on perfect levels of play I'd be one of the first people to worry, i'd probably the first one to get kicked out of a perfect group!
Finally, we don't necessarily need a combo. That doesn't mean that there aren't other options , whether it is dots, or procs, or additional OGCD damage buttons, or buffs, or DPS or longer CDs... so why close our minds and say that nothing can be done for only the healer jobs? Interestingly enough they were very creative when it came for PVP and the healers, i don't see why it can't so in PVE as well.