This is something I don't get. Ok, let's say they don't include his mastery of the dark arts, simply because it might not fit into their established world. What you're left with is still a resourceful and scientific genius, that built his own armored power suit, robots and all kinds of other high-tech machinery. Basically an evil Tony Stark.
Why can Marvel give us a believable scenario, where a captured Tony Stark built his first armored suit in a cave, with a fraction of the resources the Ruler of Latveria would have had, but all Fox can come up with it anti-social programmer, and yet another accident that gives him his powers.
This whole Movie better be just an attempt of FOX trying to play chicken with Marvel. FOX want a decent paycheck, if Marvel wants them to hand the rights over. But obviously they are not willing to pay whatever FOX is demanding.