Printers Managements

I have a group of network printers, and i allow all of my users to print to these printers.
Some of my users start to set the print job priority to jump over other jobs.
How i can conrol this, i tried to set the “Deny” manage documents in the Printer proprties, but the jobs strat to be deleted automatically as they enter the queue.
Can i use the Group policy to control this.
Also how i can prevent any user from installing the printers.
because i have a printer in each lab, and i want the Administrators to be the only ones who can install them.
Emad