If you have an exceptionally large ship, using ASAS to manage control systems and SAS to stop wobbling would be a good way to use them both effectively.
Sketch-Up works, but not directly. I recommend getting a .obj exporter where you can export to a modeling program with a UV texture mapping and unwrapping system.
I would assume it stands for the Z angle, so it has to do with the left and right rotation. X rotation = forward & back/up & down Z rotation = left & right Y rotation = clockwise & counterclockwise