I'd love to animate this and yes this is a "holy grail" quest for me. As is often the case with such mythical quests, it is the journey rather than the completion that is important. At least that is what the sages who have still to complete a quest say!
Thus far the clouds are about right, I agree about the vortex being a little too sharp , tweeks are being applied.
The hardest part with any of these "from orbit to land" shots seems to be the camera animation. Getting that smooth curve is a bloody nightmare. TG's graph editor is a pain to use since it can't smooth curves properly yet (?!?). This means that the only way I have found so far that seems to work is to animate in reverse. Start where I want to finish the animation and move the camera backwards, doubling the distance each time (keeping the time between key-frames equal). So to continue I have to model the end environment, final tree, forest, local landscape and then get the camera to fly smoothly from tens of thousands of miles an hour at the start of the animation to a crawling pace at the end.
Easy !! I may be some time lol