I've just gone 1.0 and released this mod. You can find it on the Steam Workshop here. Continuing my tradition of ignoring game balance, this mod contains rooms that are entirely about flavor; it's the rooms where monsters live and sleep (well, no beds yet, so not sleeping) and work and enjoy what little leisure they're afforded. These rooms overflow with loot (primarily in terms of crafting goods,) and hordes of monsters, and vending machines, lots of vending machines. Burglars will enjoy that. Maximum attention has been paid to the flavor text and descriptions, and hopefully you'll get a lot of the jokes and references I worked in. I've used art assets from all three expansions, so you'll need them to use it, and I've even done some very clever (I think) work with a few images of my own, primarily modifications of existing in-game images, such as turning the TARDIS from Wizardlands into a latrine stall, or making a working computer sprite from the snow-static computer sprite. I've also uploaded the .zip containing the raw files, in case anyone wants to have a peek. If you want to use the custom sprites I've made, or make a derivation upon them, feel free, just give me a shout-out when you do.
There is an error in rooms.xml In the Long Library you have "scrawl.png" where it should say "scrawl0.png"
Also, upon loading a saved game, the descriptive text in "Fancy Office 1" all mysteriously vanished. I don't know if this is a problem with the mod, or with the game itself (or with compatibility with the other mods I am running simultaneously) On a different note, I would like to suggest changing the 'maxLevel="10"'s to 'maxLevel="15"'s
Also several of the doors are sideways due to "D"s being capitalized where they shouldn't be (and vice-versa) in the xmls (though I don't mind that particular bug; its actually kind of cool). It is, however, seemingly only an issue with the rooms added by this mod (and it seems to affect all of them). (Which is a shame because I like this mod and its flavor text)
I'm reasonably sure that error was caused by Gaslamp changing the name of scrawl.png to scrawl0.png after I uploaded the mod. Nevertheless, I have fixed that error, and the inverted D and d doors, in the mod, and I've uploaded a new version, both here and on Steam's workshop. Per your request, the rooms now go down to 15. I figured people would be tired of seeing latrines and vending hordes, but I guess not. As for the disappearing text... I'm not sure what that's about. Someone on the Steam workshop had that problem, too; near as I can make out, it's a savegame issue that gets fixed if you start a new game.
I think I figured out part of why the flavor text keeps disappearing. According to the modding wiki there is some sort of problem with descriptive text associated with "customengraving". Luckily the functionality of "customengraving" seems to mostly overlap with "customblocker", so you might be able to correct it by changing the one to the other. Also, with both of these types of objects one you can specify passable="0" which is more elegant than putting things on top of invisible walls as the impassibility will then move with the object.
Some testing shows that I was right. Attached is a repaired version. EDIT: It seems that this needs more tweaking. The passable objects now need to be set as passable.