Maybe you’ve considered this, but:
If any acts are using recorded music, make sure that the recordings they bring work on your equipment, before the show even starts. (is there a rehearsal?, or some specification on the music?) (Seems to be a less common problem than a few years ago, but if someone is using a cassette and all there is is a CD player.... On the other hand, I recently saw a cheerleading squad get “burned” trying to use a recording at their own home gym! Their CD did not work with the gym's CD equipment.)
Minimize the time between acts (okay, that’s a pet peeve for me), but an extra minute between each act can really add up. But if there is judging for the talent show, there will need to be some “ready” signal that the judges can give to you (or the emcee).
You’ll probably need someone backstage to make sure each act is prepared to go as scheduled (as they say in baseball, “on-deck” and “in the hole”.)
Joe