Well, yes, those things could be done, either by adjusting/rotating the mesh, or by some Photoshop editing ... but I included all the tools so folks could do just what you are doing. I didn't think one modeler could tackle the demands of an entire community of likes and dislikes when it came to something as variable and objectable as a planet.
Again, Model.siz can make them whatever size you need for whatever mission ... as for moons in the mesh itself, either someone will come along and do it before I do, or I'll add things like this in Pack II in a couple of weeks.
As far as airless worlds, either turn off the atmosphere by blacking out the two 'a' textures or simply import the mod into max, delete the outer sphere, re-export. I'll be doing some of these things in the second pack, plus adding illuminations to the planet itself ... but as I am in the process of moving right now ... it's not going to happen overnight ... lol.
IIRC, most all of the stock planets were fairly perpendicular in alignment ... I thought about tilting the planet, but then, if someone were to ever edit the thing as a Starbase rather than a Planet in ShipEdit, then the thing would rotate on a serious wobble ... (Why would anyone ever do such a thing? Destructable bases on the planet, for one ... if the object is to capture and not destroy, this might be a set of victory conditions ...)
JM.