To be honest when I was first running the healing jobs I wasn't comfortable dpsing, and I didn't trust the fairy or really understand her limits so I would spend most of my time healing, and put dots on the mobs without switching to Cleric Stance. It was only once I got both healing jobs to 50 and got more practice that I felt fully comfortable and confident with my own abilities, the fairy, what we could and couldn't do, and what the tank could take (and what I could bring them back from).

No one is excellent at anything to start. It takes a lot of practice, sometimes some screw ups, and learning and trying to do better. I'm happiest in a run throwing out an Adlo, switching to CS, and dpsing my heart out before I switch back to top off the tank. But not everyone's there, or trusts themselves (or their fairy) that much.