I recently rolled a Shadow Priest with a full set of heirlooms. The reason I went shadow is because it's simply easier to level with when soloing/questing in comparison to Discipline or Holy. Once I reach level 85 on this particular character, I'll be playing the role of a healer in Holy spec for the majority of the time.
My question is the following: I'd really like to start healing earlier, preferably as soon as I can queue for instances. Can a Shadow Priest get by as a healer in pre-Cataclysm instances until I get dual talent specialisation?
Will I be getting my group killed if I do that?
Any advice would be appreciated.