So right now ghost sims are a bit lacking. I've killed off a few sims to have their ghosts on lots as NPCs and they don't function much different from normal NPCs except that they have a few ghost spe...
Not being able to create ghosts in CAS has been bugging me a lot, i want that. And i miss Sims 2 where a ghost would scary our sim and they would die of fright if they see a ghost. Actually, all of your ideas are really cool and i hope they add that to the game. Maybe they could add some gameplay for us if we wanted to keep playing our sims even after they are dead, like a Netherworld or something!