I wouldnt feed exclusively meal worms. Since I breed them they would probably make up a larger portion of the diet. I would probably supplement the diet with earth worms. Just kind of alternate the feedings.

Ive heard that pacman frogs are pretty aggressive so I am kinda not so sure about them for a classroom. It would not be good if it was to bite a student. I know that I can get fire bellies at a local pet store. He might be able to order others.