to mitigate heal spamming w/o overcomplication:
every time a player gets hit all the wounds from that hit go into a single injury pile. then you can say all healing with spells can only be used once per injury just like cure insanity works once per insanity. for regular healing let the player choose how he wants to heal out of each pile. it might not be realistic but who cares it avoids complicated extra rules. the worst thing that happens is that there is a little extra book-keeping a the end of the session. the gm should just have the player's right down their injury pile contents on a sheet of paper to keep things honest.
i tried to make sure to look through all the house rules on healing but i am sure i missed some so if someone has has already brought this up then i am just saying i agree with you. (be kind: this is my first proposed house rule ever:)