I have a cabin in 30A 26 miles from the border. I hunt constantly close to or on the border and have experienced no major issues over the last 11 years. There is a lot trash, occasional illegal and very very rare suspicious subject. Keep a high profile, exercise a little sense, avoid contact, let someone know where you will be and enjoy yourself. If you see a lot of recent traffic, paper, bottles etc. . . Don't camp there. The travel routes illegals use are fairly easy to spot ( unless you are the government ). I feel safer there then when I work in Detriot or LA proper. Most of the coments (most) are from parties who have never set foot but "know someone" or "have a buddy" 30A has a ton of private land so do your homework and harvest a great one.
Best Wishes.