I think it would be nice to have the option to play a game where the dungeon is only five levels deep; sort of the opposite of Realm of the Diggle Gods. Instead of encountering Dredmor on level 10 or 15, you would meet him on level 5.
I think that would put a lot more pressure on what skills you choose to level up, as you won't be able to max them all I like it!
Probably relatively easy to mod by someone with mad modding skills. Are you suggesting condensing item selection and drops as well, because that would take considerable work. I have gone as deep as 7 or 8 before even finding a grinder on NTTG. And often times decent gear to complete your ensemble takes many many floors to fill out, especially amulets and rings.
No. I'm just saying to have an option have dredmor (likely a special, less powerful version of Dredmor, similar to how RotDG has a special more powerful Dredmor) show up on level five; everything else the same, just like checking or unchecking the option to use the extra levels from RotDG. Also, I'm pretty sure this couldn't be done with jist a mod, and even if it could you would probably have to change branchDB.xml and there don't seem to be any guides on how that particular file works.
There's a mod that spawns Dredmor at DL01, killing him triggers the end sequence and the like I think someone could conceivably mod the DL05 rooms to not have a stairs down, and a weakened Lord Dredmor.