All of the above are pretty accurate. Most places that charge a min. price per day use 3 hours.

Make sure you have full rental coverage for yourself through AOPA/Avemco. If anything happens, you will be on the hook not only for the damage to the plane, but for the lost revenue. Find out the hull value of the plane, and insure yourself accordingly.

If the FBO tells you that there insurance covers you, it's very likely either a) a lie, or b) an employee that does not understand the insurance policy (and has likely never read it).