What are Bolaire's alternatives?
A lot of people are talking about the horrific implications of what Bolaire does to survive, but I haven't seen anyone talk about what other choices are available to him. I wanted to bring this up because Bolaire has clearly thought about these alternatives, since he brought up to Hal before The Stab that he could choose not to put Bolaire on a new body, so long as Hal didn't leave him in the sewer to be found.
The choices that Bolaire has available to him, other than body snatching, are:
Find a way to destroy himself permanently.
Find a way to have himself sealed away in a dormant state.
Allow himself to be used as a weapon again.
Option 2 is, for Bolaire, pretty much the same as option 1, since he has no consciousness or life when he's not being worn. The main difference is that option 2 could be reversed, which would land him back in option 3, or body snatching again.
I think it's pretty clear that Option 3 for Bolaire would be a fate worse than death. The life he led before he ran off with Castep's body, if it can be called a life, was nothing more than slavery in service of mass death. And if anything, he got off lightly compared to how bad Option 3 could get for him. Can you imagine what someone like Primus Tachonis or Yanessa Halovar would do with Bolaire? It'd be a lot worse than simply being wielded by a soldier to slaughter the enemy.
So let's return to options 1 and 2, because there's a strong argument you can make that these are Bolaire's only ethical choices, and furthermore, Bolaire himself has intense body dysmorphia and doesn't actually enjoy snatching bodies, so he's surely contemplated these options.
Option 1: suicide. We don't actually know if Bolaire can be destroyed outright, and Bolaire himself may not know either. There are high level spells like Disjunction that can destroy magical items but with legendary artifacts and such, even a ninth level spell like that is not a guarantee. But let's suppose Bolaire wants to give it a try: how would he achieve this?
Well, to even have a shot at his assisted suicide actually working, he would have to recruit the assistance of a high-level sorcerer or wizard. So his options would be the Sundered Houses or the Penteveral. But these options are both very risky. Bolaire fought in the Falconer's Rebellion against the Sundered Houses, so he would distrust them, and rightly so. He would have to explain his nature to anyone who was going to help in the assisted suicide, and once they knew that, well, who knows what a Sundered Houses sorcerer might choose to do with that information? And until he became friends with Murray, which was very recent, Bolaire didn't have anyone at the Penteveral either who he could trust to definitely just aim to destroy him instead of turning him into a magical experiment or a weapon. And even now that he has Murray, she's a third-level wizard and definitely doesn't have the juice to have any chance of destroying him permanently.
Now let's consider Option 2. The benefit of option 2 is that you don't have to be a super high powered wizard or sorcerer to be able to seal Bolaire up in a box or something. The problem with option 2 is that if your Bolaire storage solution isn't absolutely airtight, someone could find him and get him back in the situation of being a slave / weapon / magical experiment. Once again, we run into this problem: who could Bolaire trust to know his secret and do a proper job of putting him away forever? Up until two days ago when Bolaire confessed his nature to the other Schemers, he had no one he could trust with that. It's notable that, as soon as he did have people he could trust to do that, he told Hal before The Stab in episode 22 that he trusted Hal to put him away somewhere safe if he didn't want to put Bolaire on the Crow Keeper. So Bolaire became open to this option as soon as it was viable. Could Bolaire end the campaign by surrendering himself up to Hal to seal him away somewhere secure forever? Very possibly.
I wanted to lay all of this out because it makes it clear that while Bolaire's choice to murder people to survive is, uhhh, troubling to say the least, his other choices have all been absolutely dogshit until about two days ago.