For now, I just reinstalled my PX3 with the longer GPS cable, at least that part is sorted. I may just order a new PX6 unit and have them RMA my current PX6 for a refund.
UPDATE:
Guy is THE man! Fixed my issue, PX6 is installed, with the longer GPS cable. Factory nav works, PX6 "Google Maps" nav works. Backup camera works.
I had to shift my truck from P, to D, back to P really fast, and work through the process of a simplecan update. Took awhile of shifting to D and right back to P, and getting 1 prompt further in the process, but once I hit "MCU Upgrade" on the System screen, it updated, rebooted and works as it should.
To fix my backup camera- I went into Install, code 666888 and set Camera to VGA-RGB instead of whatever the other setting was and now my backup camera works.
I havent gone through the process of updating all my apps, and installing others, but switching between Google Maps, Sync3 and YouTube seemed smooth and rapid. Much faster than my PX3 unit.
AGAIN- big THANK YOU to Guy for helping me.