PS3 targeting needs to be redone!
It is impossible to heal a PC who is not a member of your party because the targeting in this game is a joke. Dear Director, please listen to this post and implement a better targeting system for the controller.
Down on the D-pad should scroll through your party, left on the D-pad should scroll through un-aggro'd mobs (yellow ones) while right on the D-pad scrolls through the aggro'd mobs (red/purple ones). Up on the D-pad should scroll through all NPCs and PCs that are in your area and not in your party. This way PS3 players can actually target PCs who aren't in their party. I haven't played with a conjurer, but I made an arcanist and it was near impossible for me to target another PC.