Is it possible to ferment chilli-peppers and produce a liquor with a alcohol content and also a hotness?
This isn't quite what you're asking. I don't think chili peppers have enough sugars in them to produce a strong enough fermentation on their own.
I made a chili-pepper beer, which was absolutely fantastic.
I made a simple, low-bitterness beer. After fermentation was complete, I racked into a secondary and added 4 types of dried, frozen chilies. I sampled the beer every day until I thought it was hot enough and then bottled it.
The beer wasn't too hot (though it could have gotten hotter if I'd left it on the chilies longer), but had a fantastic spice at the back of the throat. It was delicious, and went great with summer barbecue.
I believe chili peppers would qualify as an adjunct. I would treat it like any fruit/vegetable/spice beer and add it late in the boil. Start small and increase to hit your target flavor.