I play several healers and I don't think MSA is necessary unless you are going to be attacking quite a bit. If you are actually healing then the energy return from compassion will be more than sufficient, assuming you are in support role. If you are worried about it you can take iniquity with the advantage as well as the…
Sad to say, but honor does NOT proc on drain w/vampiric advantage. I recently respec'd and ran out of the powerhouse to catch a rampage so Fate has it and it does not work.