Very interesting D, i'm subscribed.
I tried this a few years ago, for the same reasons as you (humane), but it was prior to getting into shape. With that, I only had to worry about eating 'to survive', I didn't have the added worry of building the body I want.
I stuck with it for a good 4-5 months, but am sad to say I fell off the wagon eventually... as you know, my will can be weak and I got really tired of eating fish and eggs all the time...
I wish you the best of luck man. You're already a stand up guy, but the reasons you are doing this only reinforce what I like about you. Compassionate, caring... you have a conscience.