2) The benefits of cooperation probably still outweigh the risks for him, he got RC out of us already, and we're clearly willing to work with him. I don't think he's soured on us permanently yet.
Something I'd like to emphasize here is that by now we have a reliable pattern of coming to Orochimaru with shinies in hand and saying "would you like to cooperate?" Dragon parts, runecrafting, even Force Dome we just up and gifted him recently.
Now, these are all considered decisions on our part, and we're well aware that Orochimaru being stronger is an intrinsically negative thing for our goals (just often instrumentally positive), and we may stop this train at any point. And we're certainly not sharing our best stuff with him, like Time Runes. But still, the pattern we've clearly established by now is that we keep giving him shinies every now and then whenever we're working towards broadly the same goals.
If you're Orochimaru, you'd wait to see how long the free loot train keeps up, I'd bet. We're still predictably concerned with other threats like the Great Seal, we're still in that same situation that seems to automatically pump value out of us for the sake of expediency. We wouldn't backstab him unless we made enough progress on the Great Seal that we knew we didn't need him anymore. Even if he doesn't trust us, we've made a compelling case that we're a fundamentally predictable individual who's quite profitable to stay on good terms with.
Hahaha wut?
Hazo knows ~nothing about biosealing, can you explain why you are so confident that we can easily undo anything the best biosealer in the setting can do?
The angle I'm coming at this from, aside from "bioseals need maintenance so we should be able to just let it run out", is that bioseals don't sound very subtle. Like, tattooed on your skin, carved on your bone, even just perturbations of our internal chakra flow detectable with stuff like MS8, I think there's a good chance it's just outright impossible to make Hazou unaware that there's a bioseal on him. This means that we can verify our wincon (being bioseal-free) and figure out how far away we are from it (locate all bioseals in our body). The question, then, becomes "how creative do we have to be about getting them out of us?", and I think our toolkit for that is actually pretty decent. Like, I bet in a more extreme case Noburi could simply rip a patch of our skin off and graft on a replacement. Put him in a controled environment, give him time to research the problem, I wouldn't be surprised if that does the trick. And that's before we even touch biosealing ourselves.
As Naruto once said, it's folly to assume S-Rankers are omnipotent in their field of specialty. Can Orochimaru install a killswitch in us? Certainly. Can he install a kill-switch in us that doesn't require maintenance, cannot be detected even by unprecedented medical seals he knows nothing of, and can't be removed even with the dedicated effort of a talented biosealer and a talented mednin fully focused on it? Personally, I doubt it.
