2) In the classic haunting, the dead character lives out his story in relative isolation. Classic haunting stories have one ghost, and possibly multiple people being haunted. Interactions between ghosts are rare and confined classicly to reliving the past. One of the biggest problems I see in well written RPG material is the failure to consider how the game plays out with multiple player characters. You simply can't expect to play out a haunting scenario with a group of ghosts with widely different backgrounds and differing motivations.
I've never played WtO, but that actually sounds like an interesting premise for an RPG: The group creates a single, history-laden location. All of their characters are ghosts in that location and may, or may not, have had any contact with each other during life. The trick here is that it's a competitive RPG: The PCs all have something they're trying to accomplish through their haunting, and these goals are likely to conflict with one another.
At one end of the scale this could provide fodder for some amazingly dark, gothic roleplaying. At the other end it can give you Beetlegeuse. Lots of range.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.