The only post work I did was to increase the contrast because the atmosphere was sharp and did not blend into space. I almost always have to do this. This is also why the stars look "off" (and I agree with you about that).
As of yet I do not have a "sharable" tgd. I will tell you that this image has 7 cloud layers -- which increase the render times a lot. That last render took, if I remember, just a little past 9 hours (cloud quality at .5/atmosphere at 30/ render quality at 0.9/ GI 2). And the closer the camera is to the surface, the longer the render time.