So, my read of these posts, combined with your initial analysis is this:
- Village has a dedicated hunter squad, headed by the Very Scary Zabuza
- ...which means that the Village inherently values capturing/killing missing-nin, in and of itself.
That is one possible conclusion. But hunter squads could also just serve as a revenue source for the village - it is not only Mist that pays bounties, after all! I'm pretty sure most villages have at least some ninja devoted to bounty hunting.
- Thus, even if one particular group of missing-nin tries to make themselves very costly to capture (such as, say, Hidden Village in the Swamp of Killing Everything), the value of capturing/killing them is greater than just their own particular values.
Yes, this is covered and addressed in section 4, under Benefits. There are standard benefits for killing missing-nun in general, but it's hard for them to apply in our case.
- We may be (relatively) worthless to our home village, but the other ninjas who were there are not
The benefits section considers our aggregate value as a group, not just the value of us the single genin.
- Seeing a large contingent of ninja all go missing-nin and founding their own village would be Very Bad for morale/loyalty/whatever
- So the value calculation needs to account for not only our own termination (which has some non-zero but likely small value), but also for the value in discouraging all currently-loyal ninja of the village not to defect (which has a probabilistic, unknown, but definitely higher value).
This is also covered in the benefits section. There is no incentive for a group of missing-nin, regardless of occupation, to advertise that they are missing-nin, much less Mist nin.
As you point out, there are only disincentives to do so!
Secondly, there is no incentive for Mist to make a big deal about our being traitors. In fact there are several reasons not to, also covered in the big analysis post. The largest is that it does not fit with their cover story and would require contrived explanations to manifest. The second is it makes them look weak/suspicious to admit that such a huge number of dudes turned traitor for no reason, both internally and externally. Their objective was to remove problem Shinobi, not create more headaches for themselves internally and out.
My guess is that our village is very motivated to ensure that we all die, though likely not quite up to provoking outright war. Additionally, your analysis of Zabuza as potentially provoking Leaf by crossing territories seems a bit thin, given that he has a well-known reputation as a dedicated Hunter-nin, and thus is unlikely to be used as a first-strike against foreign agents.
This was addressed in a later post, so you may not have seen it. I'm on my phone so can't link it unfortunately, but it hasn't been too many pages since then. Basically think about the second level implications of what you're proposing. Any nation that took such a lax view to violations of its sovereignty would be extremely vulnerable to alpha strikes by people with "well-known reputations as hunter-nin," and that's not even getting into assigning responsibility for collateral damage. Well, it's a bit more complex than that, see the post for details.
This is supported by eaglejarl's second post, which notes that the Mizukage is likely to implicitly sanction an op with disavowal, not explicitly sanction it. Plausible deniability wouldn't be necessary if the Leaf were that naive.
Also, Zabuza does not just hunt Mist missing-nin, that number of missing nin would indicate problems in Mist far beyond ourselves. He hunts missing-nin in general, taking their bounties as revenue for the village.
