Three fish questions, gourami Q, dwarf puffer Q and random feederfish?

Ook so i have 2 questions and the first is what should i do with my feeder goldfish that i randomly bought? because i read online that they will eventually eat my guppies if they get too big hahaha yeah eppic fail :P Oh wait actually i have 3 questions, the 2nd question is if its normal for my gourami to be hiding in the back of my tank and getting attacked by one of my female guppies. 3rd question, why wont my dwarfs eat anything? well. I know they're supposed to get like blackworms, brine shrimp and what not but i have tons of lil snails in there for my 2 dwarfs but i'm worried taht they're not getting enough to eat... i've had then for a week about. Yeah. >8)