I would say to keep the collar and tags. First off, the tag lets people know that the cats are current on rabies shots, so if it's a case where the cat is scared and bites, then that worry is taken care of.

Second, the neighbors/kids/whoever may get your cat back to you faster if your name/number/vet is on the tag and they can call that way, rather than calling the pound.

I don't know about your pound, but here all animals are checked for chips when they come in. It's just procedure anymore, mostly to check and see if the animal is a frequent/past visitor.