[ Unworthy and very very dead. It's not like Zabuza is doing this for Sho or pleasing him in any way by doing it, so he doesn't really care about matters of worth here, but he simply shrugs and leaves the rest of the body well alone. Offending Haku's sensibilities isn't what he's after and he really has no investment in touching more intestines and the like. ]

The base rules? No. The new vessel is part of the same collective, so they're presumably following the same objective. But Todd had enough individuality left to get offended on his own behalf, so I'd wager he had some freedom in how to dish out punishment as well.