Personally I tend to prebook all the insurance coverage needed - The Virgin Gold/Platinum all inclusive package (or similar offered by Dollar, Alamo, Airline Network etc).
I think all rental cars in Florida come with a bare-minimum insurance, required by law. However, this fall somewhat short of 'real world' eventualities.
CDW/LDW is the basic top-up. This protects you from having to pay the cost for damage to your car. Eg, you come back to the car park and find someone has driven a truck into it! (I have actually seen this happen!!!)
SLI/EP is a supplementary or top up insurance which brings the protection from third party claims up to $1m or more.
I think the only other insurance I have normally seen is PAI - Personal Accident Insurance. However, this is usually unneccessary as your
travel insurance should provide sufficient cover.
SLI and LDW are very much advisable. PAI - expensive and not required.