Oh, no, you can still use, say, the wizard class if you like. You just cant cast any spells outside of specific safe zones without YOUR HEAD ASPLODE. You get the Supernatural Exchange feat for free and can bind a spirit in place of your normal spell slots.
Note: I may or may not open up any safe zones in actual play.
Again, I generally hate pegging stuff to classes. but in terms of mechanical utility...
Warlock - on the weak side, but I'll probably do some sort of tiered gestalt as per
@Tekomandor 's suggestion, so it's viable.
Monk - terrible and useless. A dip into if if you want to i dunno, Tashalatora or something is fine, otherwise, avoid.
Dread Necromancer - I love them, but they're harder to play if you can't run around casting spirit wall all the time. They're decent for a fear build, I guess.
Binder - who doesn't love these? Jury is still out on bloodline shenanigans, but otherwise I'm pretty happy with them.
You have "mage" "wizard" "sorcerer" "witch" "warlock" and "adept" as terms describing someone who does woo woo magic. None of them are actually pegged to classes in Chullivan!world
To quote the esteemible Viletta Vadim: