it's an old truck so everything is dependent on the previous owners and how well they cared for it. I just recently got done with a basket case of an MJ that suffered from horrible previousowneritus.
it is a shame that they went from offering so much interior variety that you could realistically get whatever you want... to: you can still get whatever you want, as long as what you want is grey or maybe tan.
the ground is one of the wires in the harness coming off the truck. there should be 3 wires. ground, power and signal. the ground runs all the way back to the taillight.
the pump only gets power for a couple seconds if the key is turned to "run".
were you checking for power while the key was turned to "start"? power to the pump is not available with the engine off. were you checking for power at the fuel level sensor wire instead of the power wire? did you check the ground wire at the pump for ground?
if you disconnect the power cable running to the starter you can have someone turn the key to "start" without the engine actually cranking and making a bunch of noise.
seat foam is removable. back foam is not (at least not by design). I just recently converted an 88 to having headrests by swapping out the back portion.
looks like a standard torx bolt. it spent a decade in the salt and had nothing left of the splines. I intend to take it to lowes and see what exists in a stainless variety.