So, for the parking brake issue...
1. Have you inspected the brakes? If not, do that first to check condition of hardware, shoes and ensure no leaky cylinders.
2. Then, use the star wheel to adjust tje shoes so they just barely rub on the drums when you turn them by hand. It's pretty easy to do this with the rear wheels removed.
3. Personally, when I get that far, I consider it good enough. Put the wheels on. Go to an empty parking lot somewhere. Back up and apply the brakes. Do this several times to let the adjusters finish the job automatically.
I'm lazy and always forget which way to turn the star wheels after I put the wheels on and drop the truck to the ground.