I am guessing but it appears the cab may be sagging down on the passenger side. Measure to a similar location on both sides up from the ground or possibly the running boards to confirm if it is the cab or the box. If its the cab there is a front mount that sits on top of the frame and a rear mount that is a flexible system of links with bushings. If its the box the front cross sill may be missing a wooden block that goes between the cross sill and the frame.
For the door sag you probably need to requild the hinges. A bit of a pain as you need to remove the door and the hinges then rebuild the hinges with new pins and bushings. Easiest way to determine if the hinge is sprung or worn is to see if the door moves up and down at the rear when open a little ways. If it moves the hinges need to be rebuild, if it doesn't the hinges are proably sprung.
