So the dealership now says that the master cylinder needs to be replaced.
SO, I picked up a new one from O'Reilly and will try to get it in this weekend. We'll see.
I still find it very coincidental that this was NEVER an issue before I had them do the brakes, and there's no way that a new master cylinder will solve the brake light issue which started at the same time.
Anyways, I'll see what they say the dealer says the issue is once I replace the master cylinder.

 

Following..

My brakes used to lock up while going real slow when first started. Lightly apply brakes and full lock up. Since then I replaced master cylinder, rear shoes and pads. Flushed entire brake system and bled from RABS module first then rear to front. It seemed to fix that but I still have a soft pedal. I just lived to learn with it. No matter how much I bleed it's still soft. And yes the rears are adjusted.

 

All of my OBS style trucks have exhibited very touchy response when the brakes were cold. One of my Lightnings would lock up both rear wheels with just a few ounces of pressure on the brake pedal. Once the brakes warmed up a bit they operated normally. It's kind of like any Microsoft product..it has "features" you learn to live with.