You can go to the FEMA web site and look up the address to see if it is in a flood zone. When you find out what zone it is in it will show something like "9AE" or "12AE" etc the important part of the code is the numbers don't worry about the letters. For example in a 9AE flood zone there is a 1%...
Replacing a door in Florida is not as easy as up north.
The hardware and tracks must be commercial grade and the door must be 2 inches wider than the opening and wind resistant.
Gary
In addition to the Auto parts stores my town also has a tank that you can dump your oil into....
I don't know why the auto parts store would have an issue as all of these things are petroleum based.
Another option is to burn it
Gary