It is a valid distinction
Remove the sun and the moon and earth will no longer be together. Either the moon is leaving or crashing into the earth.
Remove the sun and the ISS is still going to orbit the earth.
If we were driving cars around a race track and kept pass each other on the left, you'd say one of us was "orbiting" the other?
Vertical mouse for sure.
Your arm bones are constantly twisted in the normal mouse position.