Can Nori steal from your character(s)?: Yes, please!
What kind of objects can be found on your character?: Kunai, shuriken, a small amount of ryo if there's more to be had, I'll let you know somewhere, lint, the odd scroll or two containing lessons or lists, a football-sized chimaeric spider summon by the name of Miourugumo, other spider summons, spiders that aren't summons, spider egg sacs (seasonal), manju, toilet paper, wire forged from Shizuoka spider silk, and a few bandages and medical tape probably.
Anything he'd never get away with?: The spiders, the wire, and the manju are the no-no's. He's extremely sensitive about these three items. In the case of the first, Mi-chan and other spiders probably wouldn't go willingly and can generally cause severe injury depending upon the type of spider. The wire is his preferred weapon and he's as aware of it as he is an arm, leg, or finger. Manju is a priceless possession and the love of his young life. He won't respond well to attempted theft of these three items in particular.
Additional notes: None!