Rear door rusted

Hi, I realise I should have just made 1 thread with all the problems I have but I've only just remembered these pictures.

On the off-side rear panel the bumper part doesn't fit as snug as the near-side? Any particular reason other than the metal being bent?

Also on the bumper itself how would I flatten the raised part as it keeps catching my rear door which has now caught on the corner and is rusting away.

Any way of fixing the corner of the door, fitting the lifted part on the bumper down, and making the left part of my rear bumper fit snug?

bumper corners are adjustable - the fixing bolts are on slots on the bumper. loosen all bolts and tap it in (or out).
other problem is usually caused by door dropping. Common problem. try lifting door, remove tread plate or live with it, like most of us .

Thanks I'll give this a go after work!