I like the direction this is heading in; disciplines as a set of spell rather than a single pick.

Being said I'm not fond of the damage type for spell selection drifting away from the traditional four elements. Thunder and Lightning I can see as having links to / being extensions of the traditional elements, but poison and acid damage shouldn't be part of the mix (Caustic Scintillation), and Faerie Fire is more of a fey/celestial theme than one grounded in elements.
Four Elements being Earth, Air, Fire, Water; what the Four Elements Monk should be capable of should remain strictly within those bounds.