How exactly is the spell retrieval process supposed to function without a spirit guide? Might sounds a silly question, but hey, that's what i thought.

I used to like the Shaman from 2.5e, though that was a very "on the ground" style of character; you spent your time contacting spirits in an area and asking them for information, rather than help and for occasional spell like abilities

I'm not sure how you might balance it, but have you considered the possibility of an ACF that replaces the spellcasting with Invocations that are tied to a limited number of spirits they can call up and get on board [a kind of binder/warlock hybrid i suppose]?