The dragonborns in the party are very annoyed because they can't stay bloodied no matter how hard they try.
Maybe they weren't trying quite as hard as they thought, all they need to do is step out of the consecrated ground. It covers a fairly small area, so it should be pretty easy to get out of it while still being able to hit things, plus it moves slowly and needs to stay adjacent to the cleric at all times.
Cleric >>>> any other healer esp with Divine Power. Shamans are kinda fun, but the OA heal thing can be pretty weak if your DM doesn't provoke them often and honestly they're a bit lacking in options (feats etc) until Primal Power is out.