The way to jumper around the seat belt thing (does not affect NSS) is to find the big red reset button device under the hood. It will have two yellow-ish (with tracer) wires going to the relay which are the "start" circuit feeding TO the start relay. Jumper permanently around these.
Wiggle the shift lever from P--N as you try and start if it clicks or cranks you are in the right area.........either bad switch, loose/ misadjusted linkage, or problems internally