1. One of the bookcases, which is obviously shorter than the roof/floor above it, can't be placed while the roof is there. But it works if the roof is removed, then add the bookshelf, then re-add the roof. (The other bookcases work as expected, where it can be placed under the roof only if it's shorter)
  2. Stairs cannot be placed next to a doorway. (My video only shows one type of stairs, but affects all stairs, I believe)