Bleh, you do it an injustice by comparing to Elder Scrolls.
I don't find the layout hard or busy...it's just that there are only two ways from the top to the bottom, they're at opposite end of the level, and that adds a lot of time to moving around. I *like* that it's hard to get your bearings or plan, it makes for a much more intense game.
The catacombs are much easier to survive in than upstairs, because the room with the ceiling grate only has two entrances. Or you can hole up at the waterfall bridge, that's worked out pretty well for us.
I think the design could be a little bit more player friendly...and there's a few too many long, convenient corridors to defend. But a) it looks great b) it's clean and professional from what I've seen, and c) it's functional as is and makes for a hard game.