Return line kit / Fuel Tank pickup tube /Fuel tank filler tube

1. Have determined that I am getting air intrusion overnight due to the return lines and want to get a rebuild kit. Is this one I found on Amazon a good choice for my 90 F250 7.3 ?
Delphi 7135-264 Fuel Injector Installation Kit $32.78

2. When running on the rear tank my truck stalls out if I let the tank get below 1/2 tank. Am I correct to assume this means there is a hole in the fuel pickup tube that lets air in when I get down to 1/2 tank? What is the part called that I need to replace? Is it called the "Fuel Sender"?

3. When filling the rear tank of my truck with diesel the gas pump keeps shutting off as the fuel backs up as if it was full even though the tank is only at 3/4. I can get the tank full but it takes a long time of slowly filling. Is this a problem with the vent tube? Possible to replace just the vent tube or best to just buy a whole new filler tube for the tank?
Thanks,
Chris