I'd love to see the furniture placement tweaked, as it feels very clunky and clumsy to place stuff, and sometimes (mainly in the 2nd bedroom) doesn't allow you to place items right up against the wall, which leaves it sitting out from the wall by quite some distance. This would be great to address as it really limits designing nice rooms.

And also just more choice, more items, especially sofas, cabinets, wardrobes, rugs, it would be amazing to be able to change the wall colours and flooring.