(BTW, it's just the Single and Multi scattering that do not have vector inputs.)
Oh... and for anyone wondering, Sun Elevation of 0 is sunrise and 180 is sunset.
Ah! Sun Rotation allows you to change what direciton is "north/south/east/west"
.. just noticed that :D
Texture Coordinates into a mapping node is usually how you move mapping around, which is why I was surprised not to see it.
I guess the thing that struck me most though was that "north" was in the negative X direction, which I thought was an odd choice for a default.. I would think north being positive Y made more sense to me as that's the direction I'd think of as north when I'm modeling, which if I was going to model something to bake into the skybox, I'd want to know that so that I could model and light it the way I intended. Somehow missed the rotation initially, but I figured it out plus the texture one you showed me. I figured there had to be some way to do it, I just had to figure out what it was :D