I don't think that it's the cargo/back door; the dome light in the cargo area is the only one that only comes on when I open the glass or hatch, then promptly shuts off when I close the door and the glass. It does not turn on when one of the passenger doors are opened, but I don't believe it's supposed to do so.

I did check the under-hood sensor. Its positioning seems to be fine.

Also, I peeled back part of the interior trim yesterday to check the wiring on the back side of the driver's door sensor. It was kinked but I couldn't see any place where it was visibly worn. Of course, the only way to check for that would be to take that whole section of wiring out of the truck and visually inspect it or use a multimeter.

Nonetheless, when I straightened it out, the problem was greatly improved. The lights did not come on as often and when they did, they went back out a lot faster. Due to that, I'm inclined to believe that the problem is there.