I'd go with #4. I have a character with Soul-fire and we agreed that healing is in Soul-Fire's purview (just like Summer magic) therefore, the sponsor takes care of the pesky "medical knowledge" thing.
You're still going to have to figure out a workable healing mechanic though.
There's a few opinions on this. I like the one where you speed up healing. I think the formula is something like this:
Base =4
+ value of consequence
So, you could heal a mild in combat with a power 6 spell (with evothaum)
You could have a moderate heal as if it's a minor with 10 shifts. If you want to heal that moderate in combat, it'll cost you 16 shifts(10 to make it heal like a minor + 6 to heal that minor immediately) . So it, very quickly, becomes too difficulty with evothaum.
Remember that it doesn't change the consequence. A moderate is still going to take up a moderate slot...it just heals faster.
Probably, the officialiast way, though would be to cast a spell, spend 2 fp's and say, "you've got inhuman recovery for one scene".
Our own group hasn't come up with an official way to do healing yet...it hasn't come up in-game.