Sharpsburg is a great town to live in.
Yes GA is the Bible belt, I am sure as long as you are not disturbing others with your religion, then no one will even know. I hope I don't offend you, I am not very educated on the wiccan lifestyle.
Summers are very humid, nothing like summer in NJ. I moved from GA to Long Island last year, I was amazed at the fact that 90 degrees here feels so much better than 90 degrees in GA.
It might take you a few summers to get use to it. As far as winter, it isn't as brutal as Northeast winters, but it does get cold, and the occasional snow, a few inchs is it though, and most schools and stores close because of those few inchs.