you could be a young adult gold dragon (maybe) but I've not playtested any dragons to compare them to PCs, so if you went this way, it may be nescesary to make changes based on how it works in game (my estimate of level=CR+1 to 4 only works on creatures with CR and HD that are pretty close together (giants, constructs, and dragons pose some major problems). I think I'd treat you as a 16 HD creature even though you aren't one. Both the demons and the dragon work conceptually, there are plenty of hooks and ways to tie either into an adventure, but again, I'm worried about how the dragon will work.