Any time you have a fuel leak it will not start and keep running you have to turn the motor over until it has reprimed itself. this is very hard on the starter. NEVER crank on the starter over about 20 seconds without letting it cool for a couple minutes.
I have a feeling if your batteries and cables are in good shape and it still turned over slow after charging your batteries that your wallet is fixing to lighten up some in the form of a new starter. (hope not)
The fuel leak has to be fixed All mine has the 6.9 filter without the bottom piece even my 7.3, I changed it because of the cost of the filters,And I like to use the KISS principlebut you can just buy a replacement filter that has it's own drain valve and eliminate the bottom piece.