What about put a room in Hall Of novices, where healers can train?
Just a bunch of dummies randomly placed in the room, and losing health as simulating a given encounter, and the healer need keep them alive for a given time frame (so, dummies will get party-wide skill effects too, as protect to name one).
In the while, put also some mechanic to do as avoid aoe or move objects or anything other, and that will be great.