The quickest way for Haley's arm to mend?

[factotum]

Why wouldn't regeneration be one of Durkon's regularly prepared spells?

I'm actually curious, what other spells would he have at that level? It seems like a useful spell to keep around at all times.

Why? It takes 3 full rounds to cast, so it's not something you can cast in the middle of a battle, and once the battle is over there's plenty of time to rest and recover spells. As for what other spells he could use from that level:

Control Weather--we know he's used this at least once, so chances are it's one he keeps handy
Destruction--useful save-or-die
Holy Word--again, one we've actually seen him use, although using it now would obviously be a bit of a problem
Summon Monster VII--always handy to have some backup in a battle