Do you even need a skybox with atmospheric scattering?
yes, if you want to control the color. We originally had the scattering effect and it was damn near impossible to fully control the color
How large are your skydomes? Wouldn't that give the appearance of the clouds curving too steeply towards the earth? In your screenshot, it almost looks like the clouds are rising up perpendicular to the ground.
1) Pretty large
2) It can if you make it go all the way to the top, but it doesnt, i can show you a picture if that helps
3) Some clouds do this, or give the same effect
When and how do you apply the sun? Between the 1st and 2nd domes?
1) Sun is applied to the furthest dome there is, the back dome and is applied on top of the color
2) Right now the dome textures are 4096x672