1. I meant to say he wore it as a necklace around his neck. Sorry. O_O
2. I don't exactly what you know by that (I'm not that great with Relic lore), but when he uses it for too long and keeps using it to augment strenuous movements (like backflips), and if he does a lot of them, his energy is used up. So yeah, probably his own willpower.
3. Definitely the second type.
4. I'd take your suggestion on that.
5. Probably the royal guard. 
6. Maybe an outstanding member of the local village militia. He's been in his village up until he reached sixteen.
7. Bandits.
8. Bandits.
9. No relations. I may fix that later as he meets more people IC.
10. Maybe in the heat of battle, when no one really pays attention to what he's doing as long as he doesn't make it too extreme.
11. Eh, just imagine him taking on ten guys at once with it playing in the background?
12. Sure.