Yes, Napa does auto paint but (a very big but) that doesn't mean they'll get it right. We've bought from two different Napa stores, one store did a perfect match for my daughters Grand Am. A different Napa store did a terrible job matching the paint for hubby's International. It's all about the guy doing the mixing, not the store.

the release agents wont cause fish eyes, release agents will prevent the paint from sticking and it WILL start peeling
rubbing alcohol is great for getting rid of the release agents and helping kill the static charge of raw plastic, vinegar im not sure why but hey all the power to ya

as for mixing the paint any good shop that mixes their own paint will match your paint mix you what ya need and sell it to you i do it couple time a week at my shop