Just curious to know what that part of the game is like and what people who have played through it think. Like what are your impressions of that ending?
1. Yes, you become a paladin after Blind Betrayal and become a Sentinel by completing their questline.
2. Yes, Maxson remains leader, you can stand up to him during one BOS quest, and you can get his coat by killing him. Don't know if you can pickpocket it from him.
3. No, you can't influence the BOS direction. You can argue with Maxson over sparing a particular synth but apart from that, no, joining the BOS means supporting them though some dialogue options can be used to show you don't wholly support what they do.
A member of the Brotherhood is revealed to be "impure" and Maxson orders you to kill him.
You can argue that he's to be spared.
It's a surprisingly tense and nasty confrontation but he admits even if his impure policies are wrong, he can't undermine his position by withdrawing them.
After which, I went, "Okay, [censored] you, [censored]."