I'll talk Hamelin - from a collection point sure get as many of the cat alts as you can. Benny is pretty great in Hamelin, but a trap in Parker imho.
Ashes and Dust, not keen on him as a scheme runner only in Hamelin, there are some tricks you can pull with the split, but with your storage constraint maybe look at Midnight Stalker - this guy is worth his weight in Soulstone.
Prospectors are good, and you can maybe look at 2x for scheme heavy pools.
I have no opinion on the Librarian.