@BryonyRae thanks for doing this list! CaS needs a discussion like this
Please add the split levels and foundations issues as a bug/request.
1- Split level "rooms" have no walls in cut walls view:
http://i.imgur.com/nA9NrCw.jpg?1
2- Placing some objects on split level "rooms" is impossible:
http://i.imgur.com/xsgfdDR.png?1
it snaps to the wall over the foundation line, not going down even using cheats.
3- Let us choose a different foundation color/style for the outside and for the inside of a split-level "room"
4- Attics needs to be fixed/added as well.