I used a hammered finish enamel so 90% of those problems didn't exist for me
The recoat times are what shot me in the foot.
how did you get away with only 1 gallon of epoxy primer? Did you use High Build?
I'm on gallon 3 of epoxy primer, but the entire body was taken off, sand blasted, and got 2, or 3 coats depending on location (spots that see lots of sun got 3 coats of primer as well as 2 more coats of enamel).
I wear a dual seal gas mask style respirator with organic prefilter. Stuff's not cheap by any stretch of the imagination, but I need my lungs.
Sandpaper was where I could have spent several hundred dollars, but I didn't block sand everything for a perfect finish. I did a quick job since the hammered covers up just a ton of imperfections. When I do my QQSB 2nd gen next summer I'll be using high build after the epoxy primer and days worth of block sanding to get the body as smooth and seamless as possible.
The one major obstacle I've run into was the location where the painting is happening. My current shop doesn't have any ventilation, and cracking the door only results in dust being aggressively blown in. This results in a lot of atomized paint left in the air to settle wherever. This lends itself to lots of sanding. The next location will be ever worse, it'll be a carport connected to my single car garage.
So guns depend on what you're spraying, you NEED a large volume air compressor that has the CFM to keep up with continuous spraying, you need a GOOD respirator (preferably one that also protects your eyes as whatever gets in your eyes goes directly to your blood stream), you want ventilation that's negative pressure at the FLOOR-this way dust isn't being pulled up from the floor to the vehicle, aaaaaaand.......patience.