Ah, that works great. I set the region, did //flags noplayerblock 1 and no one can destroy blocks.
Only problem, no one can open trade-o-mats, chests, ender chests, etc... anything with a GUI it seems.
I tried setting nochest to 0, but that doesn't work. When they try to open the trade-o-mat, it gives the "noplayerblock cancelled the event" or something.
Anyway to fix that?