Wow. That is detailed... However... they're really similar to Dracans/DracoKin/Fire Elves. They could work, but there's this thing where all half-"breeds" are fertile, and a few other things, such as where they sort of elementally cross, don't exactly mesh. If you're willing to either tweak them a bit, (which will need to happen anyway, as their magic and such doesn't seem strictly Fire) or have whoever ends up being a Dragoth come from a distant continent to the west. There are a few other things that could need changing, but I don't remember exactly.