I'm not in Florida, but a google search of "Florida turnpike bicycle" turns up this link:
http://www.flrules.org/gateway/notic...asp?ID=1332215 which suggests that bicycles are not allowed on the turnpike system.
Local folks are better prepared to give alternatives.
As far as being crazy to ride on toll road or limited expressway. A bit of a moot point if it isn't legal. However, if it were it would depend a lot on the toll road. In particular that challenging parts of these roads isn't necessarily the straight parts, but instead the frequency of on-ramp/off-ramp and what happens to the route at those points.