So I went out and bought an HVLP sprayer, paint and primer, body filler, and lots of sandpaper. I went through two cans of filler and 3 tubes of glazing putty, filling about 20 dents, including a few very large ones on the driver's side (which is what that giant patch covers). I also ground out all the rust, including the entire passenger side A-pillar. Wherever there was metal damage, I used "plastic metal" to make a nice solid surface and hopefully stave off rust reformation for a while.
It's coming along nicely, despite what it looks like in the pictures.
It feels like I'm driving my friend's Carrera around. Everyone looks at me.





Tonight I finished sanding and put on the first coat of primer. It looks great; contours are perfect (so far as I can tell) and I should only need another coat or two to fill in the remaining pinholes and scratches.
Of course after this I'll have to change the hood and bumper.