Both very interesting spells!
I think an Astral Projection Evocation might get a little costly in terms of Mental Stress. Thaumaturgy is probably a better way to go and represent it with an Aspect. Also, a prefered method of many on the boards is that he wants to have a permanent ability for Astral Projection to model that as a Power that he buys, using his Spellcrafting powers as justification.
Hijacking the nervous system. Fun, fun, fun! I don't have an issue with the spell from a mechanically view or a Law stand point (though I think some people might split hairs on that). Again, a spell like that in Evocation would be costly but I think would be be modelled as a block against motor control. With Thaumaturgy it would be with consequences most likely.