It sounds like something bad could happen to this cat, on your nieghbours acount. The only place I would be sending him too, would be your vets, humane society. Not to a Feed mill, who will odds are become a mouser.,if you no longer want to care for this little guy. you never know, maybe with a little love, care and attention this cat might love the indoor life. I have seen a few wild cats, that now enjoy the good indoor life.
Thanks for giving this cat shelter, food and water daily.