1 - Vampire shouldn't be in the same bucket as Pirate and Plaguebearer. Now, I don't have Coven, so obviously I've never seen a Pirate or Plaguebearer in action (those 30 Coven tickets I have for some reason will remain untouched forevermore, maaaybe unless some renewable way to get them shows up), but from what I understand Pirate and Plaguebearer are both variants on Neutral Killing. Pirate is a Neutral Killing that gets bored after two kills and then turns into a post-lynch Executioner with no defense, while Plaguebearer is pretty much a Werewolf with a longer fuse. Unlike Vampires, Pirate and Plaguebearer can't change the win condition of other roles. I don't think that this is something Vampires should be able to do at all, but I also can't see any realistic way to make it stop doing that. Therefore, I'd say Vampire stays in Neutral Chaos all by itself forevermore (unless something else that changes the win condition of other roles is added), while Pirate and Plaguebearer get moved into a into a new Neutral Malignant category.
2 - Add "Town/Mafia/Coven/Neutral/Any Excluding" brackets where one can choose specific roles to cut, such as "Neutral Excluding Survivor/Amnesiac/Vampire" to make it only pick from Killing, Evil, and Malevolent if applicable (probably it just says "Neutral Excluding", and if you hover the mouse over it or touch it or something it'll present a drop-down list of what it's excluding). Alternatively, for a more simple but less effective solution, just add a "Neutral No Chaos" bracket that's Neutral Any except without Vampires.