[X] Action Plan: The Dawn's Demise
Folks, if Orochimaru could just bioseal up someone and mind control them perfectly, he would have done it to all the annoying politicians in Leaf that make so many whiny mouth noises when he tries to do his horrible science experiments.
Him installing a deadman switch in the kid is a minor comparative risk. If we fuck this up and lose, the remaining Akatsuki members are going to hang Hazou by his entrails while they slowly burn all of Leaf in front of his eyes.
If we don't fuck this up and win, and Oro really wants to kill us, then we are dead. The only thing we can do is convince him (a priori or otherwise) that this course of action would be very inconvenient for him.
Hazou literally shows up to this guy's doorstep about once a year to trade cool shit to him in exchange for some literal garbage he has lying around his office (money included in that), a handful of baubles, and what amounts to a mild workweek's worth of time from him.
We are literally Santa Claus as far as this guy is concerned, except instead of leaving cookies and milk for us in exchange for presents, he just has to ramble on about random shit while passing on every fourth or fifth conversational topic.
Does that mean he will work with us? Fuck no. Does that mean he's not going to work against us? Fuckkkkkk no!
But even if —especially if, I would argue— he installs a magic "Kill Hazou" button in the kid, I would argue he is less likely to use it to murder us immediately than in the counterfactual universe where he does not have this very convenient button.
He's a greedy Essie minmaxing ninja guy. He's going to wait until he gets coal for Sagemas before trying to murder Santa Claus.