Yeah, large scale tanks allow us to pull off stuff that I'd never dream of trying in a home tank. For example I'd never suggest keeping tetras and predatory cichlids together at home, but here it works out fine.
We don't do any live fish feeds here. There are too many chances of introducing some outside funk. As for teh fish with sharks question, sharks do well as long as they are fed on a regular basis. We keep many "food type" fish (jacks, red drum, porkfish etc...) in with large sharks (sandtigers, browns, nurse) and they never hunt them down.