Perhaps, Maybe some more transportation means? I've been mulling this over and I'm thinking trains, planes, and boats? You know, have the ability to travell from neighborhood to neighborhood (I first got this idea when I bought Seasons and got the turn other sims into PlantSims hack, but then the only PlantSim being in Riverblossom) this would also make hotels a nessecity, since you can't just go and buy a house, which then arises a new concept, perhaps you CAN, like a vacation home (Not like the Vacation EP, I know many ppl despised that for the xtra useless kids, including me), but a home a way from home. Also if you make friends, perhaps you could stay at their house in their neighborhood.
With this, there would be airports, most likely subhoods, or something of the such sort. You would have hotels, terminals and runways, you could even have the little moving pathway (I Love those things
) also you could have train stations, where you could board the train, and boat docks for cruise ships, also you could own a Yacht!
The hotel feature would be fairly easy, I mean, making a door, a key shelf, and you rent a key that opens a door to that hotel room. Thus you could apply the same to apartments, and rental houses. Except you pay a monthly bill, and you could have the landlor boot you out if you don't pay that plus the regular bills.
Perhaps it could be called Sims 2 Around the World?
On the supernatural aspect, I LOVE IT! I like the werewolves the most, yet I think they could have been inmproved on, like, they grow muscles and rip out of their clothing (Perhaps like in An American Werewolf in Paris?) also, perhaps more interactions, like Maul, Fight with Wolf, and also, like if you turn another sim into a werewolf you have the beginnings of a pack, which you lead and ect.