paints and primers

I'm back in the auto restore hobbie after 20years[lots of new paints and primers whew!!] #1. I used some can primer on a 1/4 repair but I didn't read what kind [dumb]. It turned out to be a enamel primer[no hardener] I know you don't have to say it[nooby move] well here we go I didn't want to undo all my work so I put laquer primer on very dry and it didn't lift so I went ahead and put 2 coats of ppg base coat on dry waiting 1/2 hr between coats so far so good then my 3rd coat I put on wet,Yes it did lift the size of a 1/2 dollar. I sanded the area and put a 2 part epoxy primer [2k] on dry and tried again same results.I started over from scratch and now It's done.Lessons learned the hard way but If you don't make mistakes your not learning!!! NOW FOR MY QUESTIONS #1 can you use a regular laquer primer to prep a car for a bc/cc paint job to me it seems to show all the work even after blocking w/600 wet?
#2 Can I put the epoxy primer over [2k] LAQUER pimer that I already finished working with?,I's been sitting in the sun for 2 months this summer. #3 can I clean my guns a hvlp for b/c c/c and and a cheap suction for the epoxy primer with a regular cheap thinner? I know you can't leave epoxy primer in the gun for to long before cleaning. Thanx for your sharing your experience w/a mid life car crisis nooby!!

p.s. did they make dual exhaust for the 1985 riviera w/307ci engine or headers? And If so would it make a big difference in econemy and power?