Are the DJs using MC through the regular computer interface? If so, you can engage Party Mode: View > Party Mode.
This makes everything read only. Playlists can't be changed. Metadata can't be changed. I'm not sure if play counts and last played date are updated, but I'd suspect that they are. Essentially, in Party Mode, everything can be played, but nothing can be changed or deleted. Like you'd want at a party! With a bunch of DJs.
Party Mode is password protected. There *is* a back door to get you back in, and any sufficiently motivated DJ could "crack it" by looking this up. It's not perfect, but it's pretty good.
Good luck.
Brian.