Would be practical if we could select multiple elements (walls) with ctrl+click, then copy/cut/drag or edit(?) them all at once. Of course, when pasting them, all the original relations should remain.
I know this is kind of possible now. But only by using the rectangular selection field, which isn't a flexible option (since we can't unselect discriminately).
Also, when selecting multiple elements, would be useful if the angle between adjacent walls would show up...