First, you can get seaworthy used boats cheap down here. It's a buyer's market and it is glutted. Second, if you are going to actually castoff and leave the dock, you'd better get some experience and know what you are doing. People who don't tend to keep SeaTow in business - if they are lucky. Lsst I heard, the Coast Guard would not come after you anymore unless you were sinking if there was a commercial service available.
We spent years coastal cruising , first on a Bayliner 2452, then on Searay 26. The Bayliner was roomier ant set up better down below. The Searay was more comfortable under way and handled better. Both these boats were towable, could be stored in our yard and hauled to inland lakes as well as the ICW.
We used to be able to find beautiful, quiet anchorages and inexpensive, out of the way marinas. No more. Even 3 miles out, you can't get away from people. We were enjoying the tail end of the uncrowded water. The crowds have driven up marina prices, caused tensions and crowding at anchorages, resulted in some anchorages being abused and then closed, and caused a tightening of laws and restrictions. The easy-going days of the Pardey's are over.
If you want to live aboard in Florida, you will contend with constant humidity, heat, corrosion, mildew, noise, and never-ending maintainance that you REALLY don't want to put off. Everything on a boat is 3 times as pricey as it should be.
That being said, we loved it. Take some boating classes and come on down. Just make sure you know what you are in for.