1-2 years seems too much. I know it's a live dungeon that is what call me the most. I'll figure out how to run it in one year. thanks a lot for sharing your experience with me.
As others have said, you'll want to tweak a few things. I'd leave the moathouse alone and prep your players to have a "spare character or two" and let it really shine as a death trap. Gives them the right attitude to approach the main temple (cautiously, although once they have a few levels its not so bad).
If I were running it now, I'd probably turn the various temples into a "delve" (borrowing a 4E term) of 3-4 encounters each. On the fly, this simply means combining rooms into a larger encounter such as 1) water temple 2) priest area 3) guards area and treat each of those a single encounter.
Other tweaks: Level 3 (basically the lower half, non-zuggtmoy portion) I'd let player move rather freely, avoiding encounters and play up it's ruined nature a bit more. I'd keep the undead encounters and include work gangs of humanoids "clearing" an area of undead or repairing a room, etc kind of vibe. Remove the extraneous encounters or make them all mostly avoidable.
Level 4: Greater Temple: It's best played as one giant encounter in the Main Temple and the other side stuff (gates to nodes) as something to do later, so this can be foreshortened.
Main Temple (surface area). I keep the grand evilness in heavy descriptions, but I usually re-populate with undead and/or critters. I've never liked the humanoids being in there. The bandits in the tower are ok. Play up its ruined state and the sense of "the armies killed people, sealed and fled...everything is like was 30 years ago" with banners of good mixed with the war banners of evil, broken weapons, skeletal bodies littering the floors, chopped up pews, etc. On more than one running I've included a spectral "ghosts" (not MM monsters....more like a visual) of elves fighting cultists etc. It's a haunted place, a cursed place, and it should give the PCs the willies. Maybe use the fear/terror rules in the DMG for it.
Falrinth: He's the evil wizard on level 3 ( I think). I like to use him as a "patron" of sorts...he meets the PCs in Nulb. Most PCs won't trust him, he is clearly not one of the "good guys", but he does help them with intel. Basically, he wants the PCs to get the various gems from the nodes to power the Orb of Golden Death, he doesn't say that, of course (and barely knows what he wants himself, its the orbs influence really). I have found his more direct involvement makes it easier for PCs to finally get the orb and move forward, otherwise,
in a fast forward and hurried approach to ToEE it can easily be missed (which is what it sounds like you want to do). 1E was much more keen on hiding things a little too well.
