Remove oil sending unit and replace with a mechanical gauge to check oil pressure
Pump, filter, and level sending unit are one part, yes.
Then fix it
Yes.
you have to take the tran out. then it will slide off
Check engine water temp with a thermometer -- Replace temperature sending unit
Inside the fuel tank with the sending unit for the fuel gauge
You might have an issue with the 4wd shifter location, and the 93 has a foot brake instead of a hand brake, but it will probably go.
It's not fused separately. If your fuel gauge isn't working, you either have faulty wiring to the gauge, or a faulty fuel sending unit.
No, check the guage operation by holding in the trip reset button for the odometer while turning the key to run ( not start ) if they all go back an forth through all the ranges the gauge is good and the sending unit is bad.
A 1998 Jeep Wrangler does not have EGR.
I believe that is Motorcraft DY961