It might make a better fan fiction than a role play in its current form.  However, if you were willing to abandon the [i]Beetlejuice Remake with Modifications[/i] aspect of it, you might be able to find some new ground worth exploring.  

For instance, what happened after [i]Beetlejuice [/i]ended?  The afterlife is bound by rules, bureaucracy and guidelines (as expressed by the handbook and the afterlife facility in the movie).  What happens when there is a rogue ghost that gives even Beetlejuice the chills?  What happens when a phantom breaks all the rules and tries to make the afterlife an unliving hell?  The players, other ghosts with other sordid histories, would have to come together to put this rogue poltergeist down and who better to help them than the Ghost With The Most?

Or

What happens when a radical, dangerous holy person decides to declare all out war against ghosts?  He and his militia of devout followers are going haunt to haunt exorcising spirits and attempting to bring an end to the ghostly plane.  The players, as targeted specters, have to find a way to put an end to the holy person's crusade before their souls are erased and the only one they can turn to for help is the notorious Beetlejuice.

Or

You aren't the ghosts, you're the family or a group of friends or a team of modern day ghosthunters tasked with spending the night in a known haunted location where Beetlejuice and others of his ilk happen to reside and your goal is to not only survive the night but come out with evidence that Beetlejuice, and ghosts in general, are real.

I think there are several avenues to build a fandom RP out of it.  I just think setting up a remake template and putting players on both sides of it (Some humans, some ghosts haunting and provoking eachother) might prove challenging to play out.