Good catch.
I have made it a point to either use lock washers, Locktite or both on the steering box bolts. I have had them come loose too. While this explains the spooky steering feel, it still leaves many questions unanswered regarding the alignment. I didn't mean to "shortchange" you regarding my earlier post about alignment specs. Clearly, you need some negative camber in any street driven Mopar that you want to handle well. Your car was built when Radial tires were just getting more popular and the OEM alignment settings were not much different from a Bias ply tire equipped car. Drone auto techs that simply align old cars to old specs should apply for work at Wal Mart. The rules have changed. We can make an old car handle as well as a new one with better tires and an updated suspension as long as the alignment is updated as well.
Negative camber on its own will not result in increased tire wear with radial tires as long as it does not exceed .75 degree. It is excessive toe that eats tires! Negative camber helps straight line stability as well as cornering ability. Positive caster is essential too. More caster means the steering wheel will want to remain straight. Turning effort increases, as well as the steering wheel wanting to return to center after a turn. You WANT this! The amount of caster you can get is limited with the stock eccentric bolts and standard bushings. Aftermarket tubular adjustable arms add a huge amount of adjustability.
Toe IN helps keep the car stable, wander less and it also offsets the drag the tires have. As the tires roll, they may want to push back, causing a "toe-out" situation. Adding a bit of "toe-in" is sort of a preload against that.