If I might give some suggestions about models further enhancing your Eldar range:
A single segment-wide double-sided wall entity
1. If I do a room with an archway on each segment on 2 opposing sides the wall can be put up against the back of the archways to create "recessed arches" which would make very "classic" looking fantasy rooms.
2. It would also allow dividing a room into smaller parts, as it is now I need the columns to close the end gaps of back-to-back walls. Imo this wall can be perfectly flat to make it easier to modell.
A stair
I know its not as fancy as the things you allready announced but it'd make the segment complete somehow.
But whatever you do next, I am sure it will be top-quality
In case you find my grammar and spelling weird ---> native German speaker ^^