In order to add a bit of extra game-play experience, I believe that each world type should have Faith buildings that tie to the World Type. For example, I believe that Spice Worlds should have buildings dedicated to the Sandworms/Spice Deity. When a world has enough Faith, it should help with increasing colonist happiness and contribute to keeping a settlement socially stable. If Faith gets low, it should increase the amount of instability in a settlement accordingly. An example of this could be a Spice Shrine for a Spice World, and this could evolve into larger buildings or even increasing decorative varieties that contribute to Faith. If anyone else would like to discuss this more, feel free to reply to this.