1. The option appears after few first days if I remember correctly. But there is still a bug that prevent people to see the list unless they save/load the game. It should be fixed in 0.16.
2. Eventually there will be a bonus with having them high or low. I didn't have much time to do stuff around this mechanic unfortunately, but I'll be improving it and adding new stuff with other enemies as well.
3. Encouraging him to go to the bandit camp locks him in bottom route. Discouraging him leaves him in his normal route. But it's romance route, so it's going to take more time to do stuff with him. Like with Bernard.