Yeah, i visited rusty as well. Still have quite alot of locked doors that i cannot open, but it appears i have visited every place i could, and talked to everyone. Even the "library" and cinema, but besides the keg, and 1 person, there is nothing there.
You should have talked to the following characters:
Sarah and Mel in the lounge
Derek in the lounge (not 100% sure about this one)
Riona in the corridor past the bar
John Boy in the corridor past the bar
Nick in the library
Jacob upstairs
Heather and Ashley in the room near Jacob
Mona in the room to the right of Heather and Ashley (get her a beer from the fridge)
Tommy in the hallway past Sarah and Mel
Rusty down the stairs near Tommy
Tommy again, this time with with Quinn next to him
Best I can do, I passed that section a long time ago.