This is all very helpful. I'm looking at various clips of skiing . . . when the snow is worse and when I'm skiing slowly (like the clips above), I definitely am seeing more of this pattern, with the skis pointing in somewhat different directions at some point in the turn. But in more predictable, consistent snow, or when I'm really skiing quite aggressively, it seems to go away. I'm guessing the challenging conditions (and maybe slower skiing?) are exposing my flaws.
In any event, I'm going to dedicate some time to focusing on my inside ski and my balance - particularly while we have no snow in the northeast. Based upon what I've heard, I will: (i) focus on dropping my inside knee a bit more and bringing the inside ski back and perhaps a bit closer to the other ski (which I believe should make my inside ankle have more dorsiflexion); (ii) practice some side slips and 360 drills (I will look that up); and (iii) focus on not sticking my butt out, to the extent it become apparent. If there are other things, please let me know, and thank you all. I am also working a bit more on my carved turns on the steepest resort slopes. I usually have no problem with that, if the snow is decent, but again, when it gets ultra firm on something that its ~30 degrees, I'll often carve 6-7 turns, then have to skid one to get my speed back down...that's for another day.
I wish I had done this stuff at a younger age, but I was preoccupied with jumping off things and skiing hard, rather than skiing smart. Though likely not useful for any movement analysis, I'll leave with this clip of some nice corn skiing on Mt. Washington last spring - I was skiing well, and it was a day to remember. Thank you again all for your guidance - I have a ton of appreciation and admiration for your insight and ability to detect these issues.
Mt. Washington - Snowfields to Tuckerman