With your definition of steering, then a ski does not have to skid. I also concur that there are more ways to skid a ski than to 'pivot' it.
So many terms. If only there was a conclusive dictionary. I know TDK(?) has a thread 'what do these terms mean to you' but there is no agreement there, either.
The reason I kept revisiting this thread is because I am interested in learning and understanding the views that are influencing teaching. I must say that the KISS principle has a lot going for it as any definition you put on skiing, whether it be math or prose, is going to have exceptions, holes and variations. Nothing is absolute about skiing.
I'm glad I'm not completely off my rocker. I'm mostly interested in finding different POVs that I can utilize in my repertoire so that I can relate better to a wider range of athletes.
Now to those 4 Questions. Was it established whether the 'steering' referred to is a twisting action or the change of direction definition?