I think the vampires will likely abuse it, seeing that if the king of the vampires really wanted to conquer the mc's territory, he can likely do it. Relying on it also will probably be dangerous and all, but I do have the same thoughts as you. However, the king of vampires or whatever his called can't even manage his fellow vampires, so there's a high probability it will continue to do so whether they make a deal or not. But I do hope it turn like you said cause it really is a waste, there will be more benefits of gaining more allies than enemies .
Anyone capable of reasoning has already killed a bunch of humans. We saw it with the first vampire already. At that point they don't care about other ppl anymore. I think the vampires are similar to demons in kimetsu no yaiba, where no eating eill cause you to die. Unless in this case they can drink enough from ppl without killing them but the vampires here have been shone to drain multiple people just to level up slightly so i doubt any vampire regain their consciousness on little amounts of blood and like i said before they're mindless till they drink a certain amount so they're not capable of not harming other anyway.
I see where a lot of people are coming from, so imma throw a few more details in there. First, you dont take in every vampire. If anything, you take in vampires that are willing to seek refuge and are willing to live within the utopia mc has built. Limit their strength while in the utopia but let them have axcess to blood via working and buying it. Let them show how loyal they are willing to be and let them rise through the ranks. And, after they have shown that they are truly loyal to you (via a test or somwthing similar) at a certain point, let them have exclusive blood that only you can give them.
We dont know enough about the vampires to completely judge them yet. Yes, some have shown that they are can be cruel and think less of humans. But, some do what they do simply to get stronger because they have to. Maybe, and this could be wrong, not saying it is or isn't (this is simply an opinion), there are some vampires within their ranks that would be okay with being domesticated and living more like humans do. Id say trying it would at least be worth a shot. Experiment with vampires that are willing, get rid of any that show that they cant be trusted using mc's abilities and see if its possible to coexist. If not, then, complete extermination would at this point be reasonable and maybe even necessary.
Animals were the same way at one point until people domesticated them by giving them what they needed to survive, people when through the same evolution as well and slowly developed into the societies that we know now. So, why can't vampires do the same, yah know?
But, as Ive said before, that's just my opinion.
I know this is mostly a joke but frieren demons are simply different from these monsters. I see a lot of ppl comparing tanjiro to frieren in how they handle demons but the vampires here are similar to demons in kimetsu no yaiba where the demons can choose not to eat humans. Unlike frieren where the demons are just plain evil.
The main thing for why i think these vampire in particular can not be trusted is simply because you must drink blood to regain ur consciousness as an individual otherwise they're no different from animals. But the vampires are actually completely capable of living with humans and choose not to in this work because they view humans as food and food only. But are completely capable of drinking in moderation and choosing not to eat all humans. This is not the case with frieren demons whose innate desire is to kill humans and wreak havoc.
They still need to be exterminated then. Whether they are compelled by irresistible fate to be predators to humans, or willingly adopt a predatory culture like the giant clans of Canaan, the group must be destroyed without hesitation.
If it's the latter, then there is room for exception management - a runaway who was turned and doesn't want to live like that and will do anything to escape their fate - but that in no way obligates our MC, as essentially a monarch responsible for the lives of all his subjects, to jeopardize his kingdom and go out of his way to try and preserve the vampires.
You're right to make the distinction though. It's subtle but still true.
I absolutely agree dw. I don't think the vampires can be trusted at all, i think even if mc imposes restrictions on them when offering citizenship, it's not like it can completely control them as we've seen with the ppl who refuse to fight.
The vampires are not the same as a typical criminal like a murderer or rapist because they have a biological need to consume human blood. And get stronger by doing so, it makes no sense to willingly live among ppl that u can eat to get stronger.
But they're definitely not like the demons of frieren because killing humans is entirely a choice on their end and they don't have to drain or turn ppl to get their blood.
And similar to kimetsu no yaiba demons they're mindless beasts till they consume enough blood/flesh to regain consciousness but afterwards they can choose to not eat humans and die instead once they come to their senses. Which is why i wouldn't say exterminating them is entirely fair as it's not their choice. But from a safety standpoint its definitely the best choice to get rid of them all.
In kimetsu no yaiba they actually did mention some demons that starved to death and refused to eat humans but they never specified if the demons had come to their senses after eating ppl or if they simply resisted eating any humans like nezuko.
I'm personally hoping mc can find a way to cure vampirism, so that newly turned lesser vampires can become human again without killing someone unconsciously

So... I feel like we're missing a really cool opportunity to have the vampires as allies in exchange for blood without killing humans. Like, Mc can store whatever he wants into storage and take it out and things, so, why not take blood from strong people and store it and use it to trade with the vampires for peace or even have them become civilians? Idk if anyone else has thought of that but thats kinda where my brain went with this cause to me, killing all of the vampires seems like a waist. But that's just my opinion.