Slave Maker 3

Hey all, just started playing this one a while back and now I'm hooked. Though there are still a few things that the wiki neglects to fully explain...Anyways just wanted to see if there was anyone else here who's played it and if so please share any hints or tips you may have. Also if anyone knows how unlock more slaves to train please tell, I've yet to add any new ones to the market and I want Mai and Matsumoto dammit!