when you noticed the binding in 4wd, were you on pavement? if so, that's just the nature of 4x4, it turns all the wheels at the same speed, and when turning, the outside wheels need to turn faster but can't, which causes things to bind. that's why 4x4 is for "loose, low traction" surfaces only.
for the brakes, have you pulled the tail light housings to check the mounting screws for rust? when I had issues with my brake lights, it was because of a bad ground which was caused by the mounting screws being badly rusted.
maroon 1987 Grand Wagoneer. stock for now...