I'm new to vaping (less than 3 weeks) and haven't begun making juice yet. But I have been studying and working with herbs for 40 years or so and one of the very first things that occurred to me, when I became aware that there's a world beyond free-trial cigalike ripoffs, was using various herbs along with varietal tobacco leaf to create natural, even organic e-juice. It just reflects my personal bias.
I have a short list of herbs that I want to experiment with, and hot peppers is there on the list. Not as a stand-alone, but as a minor ingredient. I even considered wasabi (but, I think not...)!
The chemical in peppers that gives them their heat is capsaicin. Bell peppers don't have any. Jalapeños have a little - habaneros are getting up there. The thing is, some peppers have wonderful subtle flavors beneath the heat. Habaneros have a fabulous fruity flavor that is unfortunately nearly obliterated by a blast of fire. One of my favorite peppers is the slightly-hot mirasol. Cayenne is the one I want to try first. (Please, please, nobody say "chipotle!") I think there's a lot of potential for this flavoring, but I'm also not much in favor of vaping Tobasco sauce. Maybe someone should say, "Kids, don't try this at home!"
Hmmm...what do you call someone who blends e-juice? We have tobacconists, perfumers, herbalists, and I call my local guy my vaporista. No matter if someone is using natural or synthetic flavors, it has to be an art. It should have a name that gives it dignity.