1) Sorry, I had meant the name and kind of meant the Purifying effect to be "soft" healing. But yes, mechanics only, this could be in Fire as well.
2) I'm approaching the poison as more of an effect of the infected tissue of a wound, so getting rid of the poisoned flesh gets rid of the poison.
3) Okay, I'll admit that to a player, it is near useless unless you do it in bulk, but that's expensive and not needed. But it also acts as reusable CC that cannot be healed.