Percolation? Heat soak? Don't drive during summer??

Ridiculous you don't need to feel vent.. remember before you did the R&R it ran fine without it...

Exactly. They can help in some instances, but there's no point spending a significant chunk of change just to have it. Fixing the ignition issue is very likely to fix the random dying.

Spend the fuel system money on gas and enjoy the car for a while!

Then do the AC to keep the wife happy ;)