Except that this whole theory breaks down because all proceeds as he has forseen regardless. If God is Omnipotent and Omnicient he CANNOT be wrong and therefore he can't "really" give you free will.
God would have to have created the earth and know everything, as well as being able to choose any path and have free will. Of himself and for himself, you can't be both.

Anyway, is there a devil? lol, pretty ridiculous.