[swamp rat]

I cant see the back side of the door but your best bet on the door skin is to just cut out corner patches rather than mess with cutting straight across and replacing the lower section, sometimes these original door skins have a tendency to bow inward after they are cut, myself and a few others have suffered lots of frustration in dealing with it, my build thread has it documented, if the skins are that bad then its probably easier to replace the entire skin.

The easiest way in dealing with the edge fold is to use a grinder to take the edge down without hitting the inner shell, then you can section the fold with a cuttoff wheel between the spot welds, then grind off the spot welds.