the door - rust wise isnt bad, you did the right thing with filler and paint etc. i suspect when you remove your masking tape you will have a lip, which is a b!tch to get rid of. lol
and the wing, the rust WILL come back, i went down your route with my nova. and a year later the rust was back. if i were you, spray this now, get it looking good. but always look out for a wing. as your always chasing the rust.
if it was on part of the chassis. you would of have to cut it out, and plate it, welding it in etc etc.