I believe in the video the developers were moving things around for the purposes of creating a specific scenario for the clip. In the game there will likely be different classes of structures, and when something like a space station is built it won't be able to be moved (this is pure speculation of course).
Getting back to planets though, another thing I would like to see is different atmosphere categories that would include things like the density (or atmospheric pressure), chemical makeup, opacity (how cloudy or foggy it is), and temperature.