Door's fucked. That type of rust is from the inside. Replace door or get a new skin put on but don't expect miracles. If it is a door from the wreckers it likely has the same problem. Door skin all depends on the extent of the rust inside the door. Unless it it is all cleaned out (near impossible) the rusty door frame will start rusting the new skin. Roof looks pretty bad. Sanding and painting will buy you some time but nothing will stop it short of a new roof skin. Box side looks like it is on the outside so it may be salvageable. Sand and repaint and cross fingers. Bumper, replace brackets and good to go. Rust is a bitch. Once it starts it is pretty much impossible to stop.
'08.5 Mazda 3
'90 Laser RS-T
'07 Yamaha R6