I very much enjoyed reading your theory first of all. It had all the elements needed to convince a non-believer.
However i just can't believe madara would risk using any type of brain washing or genjutsu or any other means of controlling sasuke. heres why...if you really want someone to do your bidding you dont black mail them or anything like that because if they ever realized what was going on you'd lose there complaince immediatly.
No, i think the thing Madara needs most is sasuke's complete and total trust. I mean what better way to make someone do something they normally wouldnt then by making them trust that your word is the word of god. religion has tought us that mind control isn't nessacary. Only faith in the one you trust and you'll die for them right? it happens all the time in our world.
seems a likely conclusion to this question doesn't it? im not saying he isnt pulling out all the stops to get his trust. That i think you've proven to be a truth.