I like the idea of creating a new world, with a new set of everything, including models and zones, however I feel that it may be too big of a task at this point.
Perhaps the best thing to do at this point would be to simply get the emulator up to quality; complete with easy (gui) tools edit items, monsters, spawn times, loot drops, etc.
I feel that once the emulator can DO what EQLive can do, then would be a good time to start modeling new mobs and new zones.
As someone stated earlier, achieving balance may be very difficult, as it is a very daunting task. Everquest was made by large teams of in-office people working on different aspects of the project, and years after release it's still not perfect.
Creating a whole world complete with new models, items and zones could take many years, in which everquest could even be down, obsolete or even completely different in so to obsolete the emulator.
It's not to say that a whole new world cannot be done here, I think it really can be done, but it may be worthwhile to simply work on recreating at least some of EQLive before attempting to model your own world.
If you get a court order to stop, then would be the time to begin work on new zones and models.
Of course, it would be WONDERFUL to be able to actually manage a dynamic world, unlike EQLive. You could set up changes in the economy, attacks by monsters, new and dynamic quests, etc. The way EQLive has been documented on the web takes out any excitement. And the world never changes, besides weak GM 20 minute events that seldom happen and very few benefit.
-CB