Continue to troubleshoot or start from scratch?

When you say "shorted to ground" you may be leading yourself down a rutty road. If you are using an ohmeter, just because these circuits show continuity / some value of R does not mean that they are "shorted."

But I would agree^^ to unplug a few things until you start to see come pattern/ thought continuity

As far as cranking.............you likely have the annoying "seat belt interlock" device which disables the cranking signal. The functional path is (battery etc to the ignition swtich) ---twist the key to start---crank signal out of the ignition switch on yellow---through the bulkhead connector----to the seatbelt reset device---out of the device---to the start relay---through the relay coil----out the neutral safety terminal----and (depending on stick shift or automatic) either to the clutch safety switch on the pedal, or down to the automatic to the center neutral safety switch terminal---and grounds when in park or neutral