I'm afraid I'm slightly behind the times, since I'm not really up on Mystic. Radiant Servant has been the healer stock-in-trade since the game came out. With the PHB domain spontaneity variant from PHB2, you can channel your heals into domain spells, and benefit from the free empower. It's worth 5 levels at least.
I've been playing a healer for a while now. My observations:
1. Divine Ward is less good than it looks. A turn to set the ward, and a turn to use the ward means that no other divine metamagic feat can be used to enhance a distance-cast heal.
2. Imbued Healing is better than it looks. It scales with your target's level, temporary hitpoints are just as good as real hitpoints. And, because it is a metamagic feat, it sets you up for that healer's dream, Twin Spell / Divine Metamagic.
3. Initiate of Ilmater is really solid. It solves the overhealing problem: the extra hitpoints just go into temporary.
4. Twinned, Imbued Close Wounds make your DM *very* frustrated. And by the time that per-round damage can out-pace your healing, you get Deny Death. Very smooth.
5. Healing reserve feats suck. By the time they work (i.e. your target is at half hitpoints) you need a clutch heal, not a 15 point heal from holding a level 5 spell in reserve. Wands of Lesser Vigor for touch up between fights, and use your spells for clutch healing.
I know I'm going to jinx it by saying this, but I haven't lost a PC yet. We're 8th level, and routinely end up dealing with encounters 3-4 above our standard rating.
