I tried a different type of pic. Some friends I know said that the clouds were a little screwy, but overall I think for a first draft type thing, it came out pretty well. http://img213.imageshack.us/img213/4933/sweetnessvz7.jpg
It's pretty good. Lightyears better than what I can do. Lol. But I agree with your friends, the clouds are a bit overdone. Everything else is great though.
Newer, better colors + more realistic clouds???: http://img267.imageshack.us/img267/5274/sweetnessva6.jpg
2nd one is way better but the reason that the clouds look screwy is becuase you mixed like 7 different types, Cumulonimbus, nimbus, stratus, etc. It might be a little better is you did some research into cloud types. Its still great though. Its not necessary for everyone wanting to make a picture to delve into deep research over it.
Take away the one color feel of the picture. Pictures like these usually look much better with full color and detail. But it looks alright so far. Just the one color thing and I think it would be much better. Unless you just blended a lot of images together.