On the front door panels, the backer boards don’t go up that high that you have to remove the vinyl from the top edge. There is a curved metal piece on the upper rolled portion to the window. As far as the small crack, a two part plastic epoxy actually worked good for me in repairs to my vinyl face pad. I tried using the vinyl repair glue, and it didn’t look as nice. You are going to have a little bit of a stiffer spot using the epoxy. You can try to “grain” it a bit with a scrap piece of vinyl, or those vinyl repair kits have texture patches in them.
As far as the frame around the weave, I used the smooth aluminum tape like they use on duct insulation. I cut in narrower than the two inches or whatever it is so I wasn’t dealing with too much stick area. I got as much of the old vac sealed chrome off as I could, wiped the surface down good with rubbing alcohol and worked the tape on those areas, making miter cuts in the corners where my pieces met. I worked it around the area good, using the back side of utility knife blade to get it in tight, then trimmed it all with a exacto. It looks great for a repair job. That aluminum tape is quite durable, and has a good enough shean to it to work IMO. You can then mask it with good painters tape, and do you dyeing.
The Sem vinyl trim does a nice job of softening vinyl and cleaning it prior to paint.
Not sure on the back panel plastic. It is ABS plastic, and repairs nice with a slurry made from other ABS plastic (Lego pieces) and you can use fiberglass mat with it to add strength.