I don't know how old your chicks are. If they are young you have certain temperature and draft issues to deal with. I'll assume you know about those and that they are feathered out. Younger chicks are also more at risk from cats, rats, and some weasels than larger chicks. Another reason to let them get some size on them.
A six foot high privacy fence and six foot high chain link fence will not slow down a racoon or possum. They can easily climb over or run along the top of either. Other predators can easily get in too but I'm just using the most obvious. I don't care if you live in the middle of downtown Atlanta, you probably have several predators around, including raccoons and possums. If you do not believe me, pick up your phone and call your local animal control. If you live outside of suburbia, of course you have all kinds of predators around. To me, safety at night is the prime reason to lock them securely in a coop at night.
I don't know how cold it gets in your part of Georgia in winter. Chickens can take cold better than heat, but they can get frostbite if their sleeping place is too drafty on a really cold night. They need a well ventilated yet draft free roost at night on the coldest nights.
Do you have hurricanes that come through? Severe winds and thunderstorms? Chickens can survive quite rough conditions outside if they have a little protection, but in the really rough weather, I'd want mine in a protected area.