It would be awesome if you could create a new room directly from the properties window. I could imagine a feature like this:
There are buttons ordered in a 3x3 grid for each direction, N, NE, E, and so on
According to the button you've clicked a new room gets created next to the current one, and the properties window is showing the properties for the new room.
The changes you've made for the previous room are getting saved the moment you've clicked the button (like pressing the ok button)
The room gets automatically connected to the previous room, there is one grid space between the old room and the new room
It would be awesome if you could create a new room directly from the properties window. I could imagine a feature like this: