I played a healer in great many mmos, mainly pvp. and I do infact find healing to be quite awesome in this game
you do have long cast times here, but use them early on when a player is on 95% seing the great awesome heal cost basicly the same as the small one just aim to get that off 80% of the time.
also when im healing and I encounter somekind of gun wielding maniac, I can most of the time hold my own. and kill them also, which is a big relief I am sick of tired of playing games. The second you are alone, you are basicly worthless as a healer.
few smugglers got me with there opener and stuns, but thats it.
also I am not level 50 yet, that might be why it does not work.
Buttomline, don't change it so it goes. Frost strike 75k frost strike 75k you died.
also both a slow knockback and ranged stun, is awesome I use them all the time