The art dealer who (attempts to) sell Delia's work is Dick Cavett.
The actor wearing the costume of the undead preacher is Tony Cox (though it's obviously not his voice).
Mid Development Genre Shift: In the original script, the film was imagined to be more like a graphic horror film rather than a comedy, and instead of marrying Lydia, Betelgeuse was originally going to rape her.
What Could Have Been: Originally, the movie was to have Lydia be a minor character and was to be your typical movie teenager. She would also have a sister named Cathy who befriends the Maitlands. Somewhere along the planning process, Tim Burton decided to take character traits from both and make Lydia a Composite Character.
Likewise, Betelgeuse himself was a lot more sinister. Oh, and he had something along the lines of a Good Twin named Swallowtail.
Though it was with a different name, that plot point was eventually used in the animated adaption.
Also, originally, Tim Burton wanted Sammy Davis Jr. to play the role of Betelgeuse.
Wes Craven was the first choice to direct before Tim Burton got involved.
Hard to believe that the voice of Lydia is also Lunette the clown on The Big Comfy Couch (a semi-obscure children's show about a clown girl and her doll, Molly).
