About the polar distortion; I cheat.
Basically, I make two different polar distorted textures of solid noise clouds - one for the upper and one for the lower hemisphere - and one undistorted texture in the middle. Then I usually alpha mask the layers so that the non-distorted texture will show up in the center, and the distorted textures are visible on top of that on the polar regions.
After that is done, I make adjustments to the contrast on the "gradient area" to equalize the contrast on the whole overall texture (alpha mask tends to reduce the contrast for some reason) and then Copy Visible, paste to new layer and adjust contrast/brightness to get the continents visible. Contrast defines the sharpness of the continents (usually takes rather high value to look good), while brightness defines the white/black ratio (I usually think the white stuff as continents and black stuff as oceans). The resulting continent map can be used as an alpha mask to a ground texture layer. For example. After the continent map is at this stage, you can manually erase things you don't like, for example little islands divided by the left/right edge of texture (they can be a ***** to colour so that no seaming occurs) and other stuff like that.
Sounds complex but it works reasonably well and is simpler than it sounds... Oh well, since images tell more than words, see attachment, it should make it rather clear what I'm doing.
The exact same technique can be applied to everything you put on your planets - oceans, cloud layers, terrain colouring layer... it works rather well most of the time. Sometimes you can notice two "lowered contrast" regions on the map left by the alpha mask, but usually you can deal with them, and when making continents it hardly matters since you're going to contrast the image to about two colours anyway. Oh, and this technique as I use it leaves the continent edges aliased. Working in higher resolution and using careful gaussian blur on the continents works on this issue, otherwise I haven't found anything overly wrong in it.
Leaving the contrast to somewhere like +120 instead of taking it directly to the max +127 also works, but it leaves the outlines of the continents and island quite fuzzy. Sometimes this can work, sometimes not so much.
Oh, and that planet looks pretty good. The rings look very recent, otherwise they would've evened out to form seemingly "uniform" rings, but if you justify the "cloudyness" by something like test fire of Death Star, then it works just fine. The starfield looks fine, perhaps a little dense to my tastes but fine in general.
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