I disagree with including Alamar and Jeddite, especially the latter, on this list. Although they have regeneration, I don't recall anyone using them in those scenarios, either from the start or later (Alamar is useful as a supporting player), where they are not prohibited. The restriction on their use of magic against opponents is sufficient. As for the heroes from Conflux, the situation is the same. And their appearance in other cities is probably just luck that happens from time to time. By the way, dismissed heroes can reappear in the tavern later. How should we deal with them?
The Necromancer faction is good even without Vampire Lords. But if they are so desired, why not allow them from the 6th week, for example.
Tanta's signature spell can also be learned in the Shrine of Magical Thought, so it could be allowed after visiting such a location.