Ok so Alva and Harkon's family will know if the Dragonborn is a vampire and Arnbjorn and the Frostmoon Pack in Solstheim will know if you are a werewolf, but are there any other NPCs that comment on Vamp/Were status?

Well, apart from the guards that think you need a tan or smell like a wet dog. Seems odd that so few people can tell when you've changed, especially Babette and the vampire in the Blue Palace not picking up on what you are.