The door mystery continues!
As far as bed placement, I believe it is so that they can alternate cabins with beds placed near the closet/near the balcony so that they can make the cabins smaller by indenting the cabins a little in the desk/sofa area. If all the beds were lined up in a row in every cabin, the rooms would have to be wider. Kinda hard to explain in words, but if you look at a true floorplan, or an actual cabin, it would make more sense.