Rk1 Sources of new spells:
Friendly Pet - Don't Fear the Destroyer - Pellucid Grotto / UQ
Frozen Venom - To Serve Sporali - Pellucid Grotto
Haergen's Feralgia - The Silent Schism - Brell's Temple
I've been hearing PG for Friendly Pet rk2 and I think for Frozen Venom Rk2 as well.
Haergen's, per Hzath below, from Brell's Temple.
Corrections to the rk2 drop sites?
EDITED: for Hzath's info.
My supposition: rk2 drops from the zone where you do the task for the rk1.
Nice list Kanan. Thanks. :)
Brell's Temple for Haergen's Rk. II, at least that's where I was told my copy dropped.