Speaking directly to your concern about printing, we have overcome this by adding users to the lpadmin group. This allows the user to fully control the printers on their machine without the need to be a full admin. The command you can use to do this is below. This command adds everyone to the the lpadmin group which allows anyone to control printers but you could simply replace everyone below with the username of the person you wish to add to the group.
dseditgroup -o edit -n /Local/Default -a everyone -t group lpadmin
As far as being an admin on the machine, it seems uneccessary to make students admins since you can curate everything they can install via self service. This way they still feel in control of the machine but all while you are protecting them from themselves as well as protecting your network from any mischievous activity they may try to perform. But I'm certain other casper admins will have varying opinions on this.