Really the first way to answer all of your questions is to start with one of my own. Where in Florida are you fishing? Florida isn't just swarming with gators every which way you look. Certain areas have them, some don't. Certain areas where they congregate can have a lot of them at one point, or just a few another. Really the answer to all three questions is yes. If you're in an area where gators are, you better be paying attention. The Pythons won't bug you that much. The Water Moccasin's can get very aggressive at times. Just pay attention. There are snakes around almost every lake you've ever fished, nothing different but the breed down here. For the most part the gators will probably leave you alone. If you go near a nest though you better be ready to drop your gear and haul butt. You don't want to mess around with a mother gator.