In my opinion, as a pretty experienced PvP Cleric, here are some suggestions. Also, note that I think Clerics are in a pretty good spot right now. The first suggestion would be the only thing I would complain about really. Obviously with the limitations of Minecraft it makes group PvP difficult and those limitations should be taken into consideration with single target heals. Healers are absolutely fine in PvE, we sit in a corner and press macros that we pre planned out. However, when you run, jump, and fight, it gets more complicated.
-Double or triple the range of heals somewhat compare with projectiles.
Minecraft lag and movement makes healing with targeted spells nearly impossible in a combat situation. Generally as a Cleric you run in circles and group heal for maximum EHPS.
-Give healer types a 300 sec mana regen CD.
This will allow a healer to be more effective in a single battle but will still leave them vulnerable to focus fire and silences.
-Single target cast times could use a 15-25% reduction
EHPS would essentially be the same but would allow for more mobility and require more precise silences from opponents.
-Escape abilities
short sprint, self forcepush, point blank and short range crowd control (disarm,Silence,dispair, confuse, etc). This would allow for a bit of escapability.
Overall, when it comes to PvP, it's Cleric or bust for a healer. Groupheal is the only dependable heal in a mass lag group fight since you have to be right in the grills of EVERYONE to heal anyone you cannot stay still and Chant. Healers are like melee hybrids right now because thats where we must fightin order to heal, in the melee ranks.
As for Megans complaint, do not let a caster hit you in the open or you should die. Healers are support and unless they up our damage you should play defensively. If the Dev team wanted us to kill we would really need some sort of slow or root and some nukes (roll druid when 60 comes out).