Body Paint prep help

I am looking for some experienced opinions here. I am close to prepping the body for paint so some solid advice will be greatly appreciated. First a little history, the car is a 67 Dart. The car has had at least one paint job and not a very good one, nothing peeling or lifting, just not well done. At 50 feet and moving it looks nice, but when stopped and up close, that is a different story. The top coat of paint is Summit single stage. This concerns me because I do not know what is under the paint or how it was prepped. My first question is, do I take it down to bare metal, or just pick a spot and start sanding and see what is under it. This is not a restoration project but rather a Retro-Rod project. The body is a clean rust free car with minimal body work needed. Mostly 45 years of door dings that were not attended to during other re-paints. My goal is a solid driver weekend Mall show kind of car, not an ultra high end finish but one anyone would be proud to be seen with. I have never done body or paint so I am way out of my comfort zone here. I do have a painter that does outstanding work, but he does not want to do anything but run the sprayer, so body prep is all up to me and I do understand the final finish is only as good as what is under the paint. With that said and due to work and not being able to do this all at once (it is a project) and doing most of it outside under an awning and being in central Texas with a moderately high relative humidly I have some concerns. As I see it I have a couple of options;
1) One ding (maybe 8-10 dings) at a time, take it to bare metal and work out any dents maybe use some evercoat metal glaze to finish it up. The problem with that is how do I protect the area, do I just use some rattle can primer to protect the metal from rusting. If so what do I do when all of the dings are finished?
2) Bite the bullet and take the whole car to bare metal and shoot it with epoxy primer then take dings one at a time and fix them over the epoxy. If I go this route, what is the best way to go to bare metal besides blasting? Do I use a coarse paper on my sander or do I use a chemical stripper then finish it with the sander.
I'm sure there are other options as well, I just don't know them.


Thanks
Bobby