Took the time to mess with it and here are my opinions and thoughts.
It would be nice to have more than one moon. Not really high priority though. We could use one moon as shooting star or orbiting space station or more. Or even as next planet passing by in the daycycle.
I know for fact that Windlight use two layers, both using the same cloud texture, to create that changing formation of the visual cloud. It would be nice to be able change those layer's texture, not having to use the same texture for both.
Cloud texture is just grayscale image. Support for color would be nice