Scripts

Will it be necessary to go through all the existing town names listed in the game's resources to check if they are present on the map?

No, it's simpler than that. I need to be at home to write it. Perhaps Dyrman or RedHaven will manage to do it before me, and if not, then I will do it.
Regarding the second point: there is a trigger for contact. Although attaching triggers to all heroes might not be ideal, I don't see another way.