it's usually up to the pub naturally. I've seen surprisingly a lot of bad healers... even when i have agro on every mob... just spam heal on me.
The worst are the healers that just for some reason want to attack mobs... idk.
I try not to spam heal on the tank unless they are taking continuous damage that needs to be healed. The problem here is that freecast for cure II doesn't come up often enough, so we try and make due with cure unless you take a big hit. Usually paired with Divine Seal is good to make it through any fight along with Regen (which helps a ton).
Attacking mobs is ok as long as things are under control and the tank isn't really getting hit or taking much damage. I've been in parties where I've been wary of attacking mobs and others where I've got nothing else to do because the tank handles hate and their damage very well. I usually end up sleeping others and putting DoTs on the primary target if I can. Again, sleep is useless with a MRD/WAR tank, so plan accordingly.
Edit: Holy hell, first post on another page. I'm not sure how I'm doing it...