I think I figured out what was making the binding and noise in the drivetrain. First and easiest thing to test was rear spider gears. I jacked up the rear axle and spun the tires, letting one spin forward while the other spins backwards to let all the movement go through the spider gears. Immediately I heard some light clicking noise. But something just didn't make me feel like it was spider gears. The clicking was too consistent and too frequent to be a chipped spider gear(s).
So I pulled the locker actuator and put a screwdriver in there to make sure it was fully disengaged. Sure enough, I was able to push the shift fork out another 1/4". Sounds like the splines of the locker were just enough disengaged to be unlocked, but was still riding along the locker collar. My guess with the binding is when I was turning, that little bit of movement to the side cause the splines to engage just enough to grab, chirp the tires, then pop out again. I was able to still engage and disengage the locker as normal and by the looks of things, the splines don't look damaged.
This still doesn't explain the 4wd lights flashing. It may be something with the ADD tube and vacuum, or it may be the t-case actuators. I gotta delve into a little more and look for some possible issues. The vacuum line has vacuum, but it may not be enough possibly. I'll measure the vacuum pressure this weekend. Anyone know what it's supposed to be?
Hopefully it's something simple and easy, so I can get onto doing more important things like fixing all the broken crap in my core support, new rear body mounts (might just do solid mounts in the rear), making the rear tire carrier, fix some cracks on things, weld in some Eimkeith LCA Reinforcements, Transmission Cooler, possibly power steering cooler, replace broken headlights that are held on by tape, relocate battery, and a ton of other little crap. Also replace my washer and dryer at home, replace the thermostat on my wifes car so we can sell it, and manage to spend time with the family.... Busy, busy, busy...