Ok so
-no there's nothing more than sleeping there with him until 0.18 which adds in more dialogue and the cure event.
-I don't believe there's anything other than working out and doing the werewolf sleep event with him until 0.18 and I don't think it's capped just doing something enough times until you either get a heart or certain amount of like from it removes it from granting anymore like.
-the only new thing in 0.17 for rhot is his sparring with grushk scene the sleeping after 22 event is in 0.18, which then another thing is unlocked before that which allows you to move forward with him a bit.
-I think so others have mentioned it and maybe hyao removed since it was useless or wasn't compatible with the new gui or something not sure but I also wanna know what happened and if I'm missing something to re enable it.
- No in 0.18 theirs more but in 0.17 there's the werewolfs in the prison.
-nothing other than the sleeping at his place. (And if you chose bernard him saying it's not safe for you there).
Hope this helped!