The entire Florida peninsula is actually resting on Swiss cheese.
Spoken as only a Texan can about Florida.
Any County assessor will have a Plat map of any sinkholes that may be known - it will affect your residential insurance rates.
Actually, Frog you are more right about "Swiss cheese", than wrong.
Florida is a limestone shelf covered with sand, and under the limestone is a freshwater river; limestone and water don't agree with each other as the water erodes the limestone.
That is one of the reasons why I personally would avoid any area where there is a standing body of water at the surface,
and I would look more towards either the Atlantic or Gulf Coast, or the Panhandle.
Proximity to known 'sink holes' will also raise your residential insurance costs.
The idea of retiring on a fixed income of Social Security and possible pension can be eaten up by raised rates of taxes, utilities, transportation, infrastructure.
That is why I suggested that you see where the retired military folk go when they retire; they know where the services are, and where the fixed cost of living is low.
As someone earlier said for you to go during the 'tourist season', and then go during the 'off season' and see what works for you.
The difference can be astounding; also, the rates of rentals as well as home purchases vary according to the season; prudence says buy during the 'off season'.