Well since in Pathfinder Healers drop from d8 to d6 hp (due to poor BaB progression) I think it makes it worse.
I'm quite happy adding the healing domain to them, since it gives them bonus spells and a couple of abilities (Rebuke Death, Healer's Blessing) which I think helps a bit, and they get class abilities which Clerics essentially don't (other than domain powers), but ultimately more or less balances. I definitely think they should spontaneously cast Cure, but considering their limited spell lists, I may revise the spells/day to be more like Sorcerers and let them spontaneously cast at will instead.
So as a alternative choice for the Unicorn I'm considering some of the following:
- Divine Shield (Su): When a healer attains 8th level the deities recognise her devotion and grants her the ability to protect herself and those she is healing. The Healer is able to cast Mass Sanctuary on herself and those she is healing a number of times to her day equal to 3+her Cha bonus.
- Resuscitate (Su): Once a week a healer can bring back to life the recently-deceased. If she can get to a fallen comrade within a number of turns equal to her Charisma bonus (or alternately Healer level) she can restore him to life as if casting Revivify (Spell Compendium).
Instead of Revivify there's the possibility of Raise Dead, but I prefer Revivify since it goes more on the field-healer concept, and has a very finite time limit of expiration. This helps balance instead of allowing them to Raise Dead before curing blindness... In effect it's like a doctor resuscitating someone within moments of death (before they're truly dead).
What do you think?