My university (engineering college) has essentially two situations involving 3d printers
The first are the official ones in our metrology lab, they are overseen by a teacher who teaches a few classes involving them, and are generally operated by students employed by the school, they are able to be "used" by students in the sense that students can pay to purchase prints from them but the students who are not "cleared" (the students who run the lab for/with the teacher) or who are actually in the class/lab do not touch them, the machines are quite expensive and I am mostly sure this practice is a liability in the fact that in-experienced students are in fact, morons when it comes to using equipment they have not used before and i would imagine if it was open to the student body the machines would not last a month. As far as safety is concerned, the lab is fully equipped with eye-wash station ( the printers have soluble support material that requires a bath in some sort of acid/base, not extremely strong but still not healthy to touch) and pretty much nothing special, its all general lab-requirement stuff, The machines are enclosed (big stratasys units) so the abs fumes arent a concern, and the lab is already setup to be safe for heated equipment (nothing flammable kept on/around machine).
The second scenario involving 3d printers is literally every other 3d printer on campus
They have absolutely zero policy on them at all.
And honestly, its not much of a problem, several clubs have them in their club room/some space operated by the club (one club has there's in essentially a storage room that was mostly unoccupied that they were granted access to use), there's a lab or two that have one set off in a corner that some students are allowed to use if they talk to the teacher who owns/operates it, and most notably theirs students who keep them in their campus housing (apartments/dorms/etc).
So that's what the university has in place in terms of policy in place but to answer the points you brought up as far as what I would say :
Student safety, if its in a classroom/lab/university run building, honestly a warning label and waiver is 100% enough, I took a machining and welding course a couple semesters ago and that is all we needed (besides lectures about the numerous ways to kill yourself and how to prevent doing so) , the only "dangerous" parts are the hotends and MAYBE the bed ( if you can even get a bed hot enough to injure somebody), yes the extruder CAN get well hot enough to burn somebody about as as soldering iron, however its not hard to avoid , a lot of higher grade machines dont run if the enclosure is open (reducing "bump" factor as the extruder wont be moving) , and really its less dangerous then any class involving any tools whether it be a mill, a drill, a soldering iron, a welder, a stove, a blender, etc.
Now for printers NOT in a classroom/lab/university run building, i would say about the same, clubs usually have waivers for other tool usage and if its not liable to the school then there shouldn't be any more of an issue
Environmental hazards: this one has somewhat more gravity to it in the fact that some plastics, most notably ABS, create fumes, and in non-ventilated spaces , could pose "some" level of risk, do I know how much risk? Not one bit, its worth researching how much fumes it puts off and how much that will affect you , those labs/classes that use soldering irons I mentioned earlier have small ventilation duct systems that are on position-able arms mounted from the ceiling and those are sufficient for the soldering fumes, I COULD see a requirement for machines intending to run fume creating plastics that do not have an enclosure with some form of ventilation/filtration system built-in to be required to have some kind ventilation system added to the room/machine to be perfectly fair.
And again that responsibility should be directed to the club or individual for printers in non university liable rooms/situations.
Safe material handling: There isn't much to say for this one, there's not much material handling at all and even then there's not much risk involved, the only thing I can think of is the acid baths for the soluble support material and that one is just restricted to selected individuals only like I explained earlier.
Signage: Some "Warning Hot Surface" labels are really all that would be something that I would consider necessary , its not a dangerous machine other then the hotend which is just simply hot, and even then its less dangerous then an electric stove top/hot plate/etc
Training: This is a bigger one for machine the school is liable for and thats really just because they are expensive and breakable, not so much for personal safety but the machine's safety/longevity I would say this is pretty important.
Policies/Product Liability: As mentioned a few times, the machines that the school is liable for and would "matter" if they are damaged are simply restricted to individuals who have been trained, that pretty much suffice's at my school, the machines that are owned by clubs and individuals , well if it breaks it comes out of their pocket/budget.
To sum up, 3d printers do not need much in terms of policy/regulation other then to protect the machine from people who do not know what they are doing.
Hope this helps, let me know if you have any other questions!