if your wild catching bluegill then it may be illegal to keep them of that size, I dont think they would make good feeders either, I use feeder guppies for my knives and other fish that would Eat them..
Wild bluegill have parasites. Unless you want your fish to get them then I wouldn't feed bluegill to them. Plus if they are only 1 inch long you may be mistaking Green Sunfish for bluegill. Either or it is inevitable that your fish will get a parasite if you feed them wild caught fish.
I keep bluegill and other native fish and I have had some problems with parasites (I have a current post about a leech like creature in one of my tanks). I do not know the law in what ever state you live in but if you caught the bluegill from a privatly owned pond there is no size limit or number limit.
I would think that feeder gold fish or guppies would be better for your gar and oscars