Sounds like you have made great progress lately. I can’t wait to see what you’ve done.
For my clouds I just found the highest res tileable image of clouds I could, converted it to a grayscale, then I use it as an alpha map and color it the same value as the sun light. Its alright but there’s really no depth to them. I’m thinking about hacking up a way to approximate directional lighting even though its just a 2d image.
The sun is just a tweaked clone of the one from Naith.