Now for a few less realistic suggestions. I don't hold out much hope for these, but thanks for reading!
  • Allow items to be grouped so you can move them around as a set without having to reposition everything individually.
  • Some items would really benefit from being scalable, like partitions or rugs. It would be awesome to fill any size gap with a single partition and always have it look right.
  • Add exits for the balcony and the roof, and allow furniture to be placed on both. Beer garden on the roof!

I realize some of my suggestions are redundant with what others have posted, but I wanted to also show my support for those ideas.