To reinstall the shifter cable, make sure the shifter is is in the position which allows maximum cable length. If the hub spacing did not change with the installation of the mod there shouldn't be any issue with reinstalling the wheel nuts on the bike, I see 3... maybe 4 threads on the drive side axle.

Show us the amountt of axle protruding from the left side. Remove the nut and show us the pictur.e