I looked at the guide, after the fact. Sadly it's very difficult (unless you knew ahead of time) to not commit genocide. Kind of disappointing. Spoiled the rest of the game for me. You really had to set up a bunch of stuff along the way.
Heh, if you come here or check the guide, the risk is there, i even put a warning in there. Still, the only needed thing is to buy the emblem in the auction, which you can do whenever, the rest is just realizing what to do in part 5, but it's not too farfetched.