"What are the rules about enslaving people other than students or teachers?"

"Excellent question. Surrounding the campus is a 'town' of sorts comprised of neighborhoods transplanted from each of your worlds. The only rule in how you treat the townies is that you are not permitted to bring them on-campus without special dispensation. None of them are as powerful as a teacher, but aside from that, I'll let you figure out the risks involved for yourselves. It'll be an adventure." 
 

"This is a university, right? Is there tutoring available for those with, uh, no prior formal education?" 
 

"Your teachers are aware that this class has been drawn from worlds with widely disparate levels of technology, culture, and educational standards, and their classes are calibrated accordingly. However, if you want to fill in existing gaps in your knowledge, the library contains an excellent selection of volumes on all topics--not just mind control--from every universe here represented and many more besides." 
 

"Are students who arguably possess multiple identities counted per-body or per-identity?" asks the cheerful girl from earlier, now totally lacking any emotional affect whatsoever. 
 

"That's a question that varies by student and by class, but as it happens, for this class, students are counted in the most numerically conservative way possible." She raises a finger. "The most numerically conservative way possible to count the initial class. The number of students is not to decrease. In addition to not obstructing your slaves in their studies, it is forbidden to overwrite their personalities or motivations so much so that it can no longer be meaningfully said that the original student is attending class." 

"Does that mean that killing them is also prohibited?"

"No, we have a highly effective death ward and resurrection facilities, murder away. As long as it's far enough in advance of class time that they'll be recovered by then. So, at least twelve hours, ideally."

"...When you say 'highly effective', does that indicate there's still a chance someone could die permanently?"

"In an infinite multiverse, anything is theoretically possible," they say, "but in practice, it's never happened, and it's been very thoroughly stress-tested by classes with greater reason to test it and innate lethal capacity than this one. Innate capacity is, of course, not the be-all and end-all of capability, but if I find out any of you have deliberately managed to test the death ward to destruction, there will be," a fractional pause, a slightly lifted eyebrow, "Consequences."