I don't know if it's possible to add each occults in 1 pack but i love all of the ideas
Elves and Dwarfs can have a new Zealand based world
Genies can have a arabic based world (i just stick with the Disney alladin)
Zombies can have a dark themed world
Imaginary friend can be in the dreaming pack someone has in mind but with that same pack idea your sim can become a temporary ghost as an already existing occult by asking this ghost sim if he/she can turn you into one yourself (similar with Life and Death that comes with the world called "Ravenwood" if you touch the pink water on the ghost part of the neighbourhood)
Maybe we can have a skeleton similar to Selvadorada as a game pack and a world either called "sleepy hollow" or "phantom hollow" it may not be an official occult we can create in CAS but it will be a very interesting gameplay (someone made a post about this)
Mummies can have a scary dark themed world with creepy stuff
As for the rest of the occults: i have to search it up what these occults are and what they do