My basic issue with healer design is this:
Currently, as a healer my enjoyment of all instanced content is greater when other players are getting hurt or dying a lot. It challenges me to deal with mana, and use my full kit of healing actions. But think about the other side, the player who is dying a lot and getting hit by mechanics - when I am in that situation, it feels bad, and I do not have fun.

So why is my enjoyment of content built on other people not enjoying it?