With less players, same number of rooms, and finite exits from one area to the other, what do we think about building out the Underdark to expand into more areas in Thera, have more exits leading out of / into it, and also create a mechanic to make it slightly less dangerous to run around in. In addition to this, I'd like to see the skies above Thera accessible to more races, perhaps through limited equipment with drawbacks (like gossamer wings) or as part of some teleportation mechanic that would allow sky travel (you've already thought about this with that blimp room in new Arial City).

Here are the benefits:
More foot traffick in this massive area would allow for more people to be able to find and hunt each other
Gives some more benefit to playing a ranger caverndweller, and an element of danger to air forms that can typically hide from 99.9% of the MUD that now may be forced to fight in the skies
Subterrainean races actually get to be subterrainean and benefit in the Underdark
More ways to get to places faster without ruining the ability to find enemies with more routes accessible to them
You could have an actual three dimensional world with people crawling around underneath, on the surface and in the sky. Finding other players would be easier and the MUD would 'feel' smaller without having to reduce rooms, combine areas, or compromise current design.

Here is an example:
Add up/down exits to Spiderhaunt, Arkham Crypts, Sands of Sorrow, Pine Forest, Northern Mountains, Sitran Mines, Frigid Wastes, Loch Grynmear, desert of Araille, Twilight Mansion, Ruins of Ostalagiah, Ysigrath.
Have descriptions in the Underdark to distinguish which parts of the Underdark people are in (north, south, east, west, northwestern, etc.)
Allow 'where' to work for all of the Underdark just before areas like Blidgenstone, Kuo Toa, Underdark Sea. So if I'm standing just before the loading bay in Blidgenstone, I can see someone resting just outside the duergar mines or just outside kuo-toa lair (but not inside these areas).
Introduce exit control - like cavernfall. Let more classes have ways of blocking escape from the Underdark, or to it. Example: paladins can do some sort of 'light sensitivity' commune, Scions can use a portal to block an exit, etc. So PK can be a bit more strategic if players don't have 100% guaranteed escape abilities.
Tone down the various nasties like dark-elven patrollers, hook horrors, and cavefishers or or give people a way to avoid fighting them. Perhaps if they took the time to collect a special robe that they wear in the Underdark, they don't get noticed by these baddies.
I don't have an answer to being able to word/recall out, but maybe let more classes sanctify rooms or allow word/teleportation with some sort of drawback or delay. Ex: I get into a PK I can't win, I run a few rooms away to lose my attacker, and when I word it takes four rounds to go through because of the extra difficulty of escape.

Thoughts?

of making the underdark accessible from more places but not making it safer to walk around in. I think that would take too much away from what it suppose to be.

Gentle walk under dark race thieves love the under dark as is. Hiding nd sneaking down there really lets you ambush the hell out of people.
I like the under dark as is, I seeit as a place that is mento be dangerous as hell for ll involved. Getting around to areas is pretty quick. Having played. Goblin, I would rather see mounts more broadly adapted. That's the best way to condense the realm without condensing it. I could get almost anywhere in a continent in a tick or three. Made finding targets very very esy. Of course, finding and doing anything to them wi. Goblin re different things. :)

Damnedipad typing, I can't bother editing