This is the ONLY time you'll see me saying "Rent a car!" versus taking the shuttle. Off property shuttles can be a nightmare.
There's no money to be made in running hotel shuttles. As such, most every shuttle bus is old, beat up, run down, and couldn't pass a DOT inspection without $50 being taped to the license plate. Buses run without A/C, bald tires, missing body panels, not a working tail light in sight... plain and simple, they're unsafe. FL DOT is very laid back... horrible about enforcing the MANY violations these companies have.
There are a *FEW* companies out there that run decent shuttles... but they are few and far between. In addition to the questions above, make sure to ask what the company name is. Pvt me with the name, and I can tell you if they're okay, or if you should stay away.