I have several friends that have recently joined the game as healers, and hearing this attitude (all over, not just here), has them nervous as hell. I tell them their job is to heal. The rest is gravy. Swap into Cleric Stance when comfortable, if just to cast one DPS. Over time you get more comfortable and push it, weaving another in and so on. It's a bonus. Healing is a reactive job, and when you're in Cleric Stance you can't immediately react.

If I'm on AST, I'll be healing, playing cards and dropping a ton of DPS because I'm comfortable with it. If I'm on DRK, only thing I expect out of my healer is to keep me alive. Added DPS is just bonus.