I'm no expert in American history, but I know that in colonial times there were many esoteric/occult movements (i.e Freemasonry, spiritualism, Hermeticism) and not only folk magic (witchcraft).
For sure witchcraft fits perfectly into Salem.
I'm not suggesting any changes I'm just curious - are any plan regarding "magic/occult" beyond witchcraft ? From what I know you've created the whole witchcraft thing opposing force against pious pilgrims. Will there be ever a white (or gray) side of occult?
* Freemasonry is not exactly a occult movement, but it was often the case that those guys was doing occut stuff, ritualistic magic etc.