Well, the prize goes to FordTechOne! I'm not too proud to admit the issue, hopefully it will help someone else in the future with a similar error. The "check your grounds in both footwells" comment made me think.
The only ground connection that's been touched recently (a month ago) was the one in the passenger side footwell as part of my installation of the GJ 3rd brake light. The kit requires a ground for the flood lights, and the closest one is located near the upfitter wiring just below the glovebox. I started taking apart the kick panel to have a look and noticed I couldn't move the passenger seat back, it was completely dead even though the driver seat still had power...hmmm. I twisted underneath the passenger dash armed with a flashlight and found the grounding point. The screw was tight, however I could press against the grounding cable and it moved slightly towards the body of the truck. When I looked up while pressing the wire I could see the lights go from dim to full power again!
Upon closer inspection, the grounding ring has a locator pin and that wasn't properly aligned to the hole when I tightened it down. It's a very tight space with a socket or wrench so I didn't realize at the time the locator pin wasn't aligned. As a result, the screw felt like it was snug, but the grounding ring hadn't fully seated against the frame. It must have have separated just enough over the past couple of days to start causing intermittent issues. I guess the problems went away when the truck was running because it was generating a better ground that "bridged" the weak point?
Doors are now locking, lights are coming on full strength and passenger seat has power - all appears to be fine again!! Despite my stupidity I'm very happy it was something relatively obvious at the end of the day. Now I won't have to second guess the reliability of the truck - just the idiot behind the wheel
I had to beat 
