I went with rubber bushings. I had been told poly bushings are too hard, you end up with a rougher ride, and they make noise.
Someone else will weigh in (hopefully) but I would think you'd have to start with the cab and then move into the front clip shimming.
Your frame may have twisted at some point.....that's at least possible. Now we really need someone more knowledgeable than me!
PB Blaster should work, it's the most popular. I only used Zep 45 since I have a case of it (used to sell the stuff and they stopped giving sales reps samples, I had to buy my own stock and use that for samples!.....company was going retail and laid off a bunch of us before I could find another job. It was the beginning of the Recession, just a bad time to be in sales).
I'd just take my time on the nuts....I hit them with Zep 45 and Zep Twister for a couple of weeks, each time I went into my garage for something else.
*Any time you get under a vehicle wear safety glasses.