The rust around the door handles will require a cut & patch. That is you cut out the bad metal and weld in some good stuff. Only way to fix this so you have the strength this area needs. I did this on 3 of the 4 doors I have for my Rocco race car. It's an easy job if you have a welder, but can be expensive if you have to pay a body shop to do it.
This is a common problem with these cars. There is a piece of metal spot welded to the outer sheet metal in that area, to add some support to the door handle. VW did not do a good job of painting behind or between the two pieces of metal. Water gets trapped in there and you have rust. Go figure.
I have a 1988 Rocco that sat for most of the past 8 years, part of that time outside. The only rust it had was these doors and the drivers floor due to the sunroof leaking. VW did a good job of rust proofing these car for the most part. This was a Chicago car so being rust free is rare in this area.