Life Debts

[Mimi Barker]

No: HPFGUIDX 99383

In POA, we find out via Dumbledore talking to Harry, "When one 
wizard saves another wizard's life, it creates a certain bond 
between them... This is magic at its deepest, its most 
impenetrable,..."

This got me thinking about all the life debts that are in place 
around Harry. Wizards whose lives he has saved, and those who have 
saved his life. I wonder if some of these will come in to play in 
books six and seven. Of course, we know that Pettigrew's life debt 
will be a factor, but what about some of these others that have not 
been in focus as much? And what happens to a life debt when one of 
the wizards involved dies? It doesn't seem that James' death 
cancelled the life debt between himself and Snape, or is there 
something else behind Snape's protecting Harry in PS? 

Lives Harry has saved:

Hermione: in PS with Ron's help
Ginny: COS
Peter Pettigrew: POA
Sirius Black: POA, twice, once with Hermione's help... (I wonder if 
this deep magic will allow Harry and/or Hermione to have a 
connection with Sirius behind the veil?)
Buckbeak: POA, but not human, so maybe the life debt doesn't apply
Dudley: OoP, but Dudley isn't a wizard is he?

Those who have saved Harry's life:

Lily: her sacrifice saved Harry from Quirrell in PS, but was it also 
the main factor that saved him Voldemort in the beginning?
Snape: in PS, does this repay Snape's life debt to James, or create 
a new bond with Harry? Can a life debt be repaid, or is it permanent?
Dumbledore: PS
Harry: POA, his future self saved his past self when he conjured his 
patronus

What others have I forgotten?