Sharks, gators, Moccasins, etc are the least of your problems unless you hang bloody fish over the side for a chum line.
The oyster bars, sharp debris, etc is a big problem but one that can be overcome by using a bit of common sense. Don't drag your toon! Stay out of shallow water and get on and off in a foot of water or so, not on the shoreline. Carry Duct Tape for quick emergency patch and a real patch kit in the car. Watch sharp toothed, spined or gill plated fish close to your boat when landing them. If you use a gaff watch that also. In short--common sense!! Be aware of tides and wind as they both can play havoc with you especially tide and a shallow flat going dry!
All that said, I used a pontoon boat for years in Florida and they work great but usually are not geared for the salt so a very thorough fresh water washing is in order each time used, especially zipper tags, etc. Good luck with your trip.