Well the fact that I have a darknut comes from my recent playings of Hyrule Total War. 
And he can start in the hero of time festival, sure. Plus, darknuts were only seen by link.
And the light arrow? the light arrow could kill lots of things of the normal world in one hit if i remember right. A hylian would be just as likely to die.
The zuna made the darknut armor last i checked. For free in fact.
Its hard to go by the game's lore because it doesn't give background to all the races. I'm following the most likely one. But if you want I can just fabricate it myself when there's already a good background for the dark nuts. I guess i'm going to have to make one for the wizzrobe i want to make too, huh? And i noticed that thing after i made the history, the voice thing. Really would be a good idea to put that in the first post.... not just as a link, mind you. I'll work on remaking his CS if I need to. But i'd rather keep the HTW version of the dark nut lore.