IMDb has a couple of interesting tidbits:

(1) There will be a studio teacher - the only case members young enough to require a studio teacher are Isaac Ordonez (Pugsley) who is age 15 and Evie Templeton. This would suggest that Evie will have a significant role (i.e. she won't just be on set for a few days) and Ordonez might possibly have a bigger role.

(2) The crew includes an armourer. An armourer is responsible for weapons on the set. Therefore,there will be weapons involved.

(3) Fred Armisen _ Uncle Fester - is now listed as appearing in episode 1 (this is the only episode he is - so far- credited as appearing in)

(4) Christina Ricci (Ms Thornhill) is listed as appearing in episode 1

(5) Heather Matarazzo (no relation to Gaten Matarazzo) is listed as appearing in episode 1 - no role identified.

(6) Hunter Doohan (Tyler) is listed as appearing in episode 1

(7) Subsequent episode cast lists suggest Morticia, Gomez, and Pugsley will be in every episode (cast lists are only up through episode 6, however)

(8) Joanne Lumley (grandma) is only credited for one episode so far.