"So they are on duty 24/7 with no breaks and no time off? How in the world do they attend class, do homework, relax, recharge, sleep, eat, etc?"
If they're in their rooms, they're on duty. It's pretty light duty. Most of the time, nobody demands anything of them, you see. They don't have to be in their room at any particular time. They're free to be elsewhere at any time. But, when they're there, the residents are free to knock on the door and get whatever service they need.
It's like being on call, but very flexibly. The reality is that most RAs can go for days with no calls whatever on them. Then, they might get woken up at 3 AM one night. Comes with the territory. If they don't want the job, they needn't take it.
In some sense that was true... I attended class, went to movies, plays, etc., but when I was back at the dorm, I was more or less constantly available - my office was always open (my bedroom was private), and I was awakened on two separation occasions in the middle of the night for an emergency - one guy came in beat up, and one girl had a seizure.
There were 2 other RAs (different floors), both Jewish, but they had no ostensible Jewish symbols in their offices. We DID have Xmas, Hannaka parties (and once an EID party). There wasn't such a polarised atmosphere concerning religion back then, but I'd never considered having a Bible study or prayer group in my office either.