Great skiing overall, 4ster. Very dynamic, with good ski performance, rhythm, and consistency. I especially like the patience you show in your turn initiations, floating and inclining through the tops of your turns and not rushing to get the skis engaged and carving until you have some real forces to work with. Failure to do this is a common mistake these days, as "early edge engagement" seems to be all the rage.
TheRusty is, as usual, accurate and insightful, from my perspective, noting your changing stance width and lowering inside hand. But I might offer a slightly different interpretation of these observations.
I don't see your stance so much narrowing in the transitions as widening as your turns complete. Six of one, half a dozen of the other, perhaps, but I think that the widening, that happens progressively toward the ends of your turns, is a symptom of something you can improve on. It is an effect of rotating your upper body into the turn, which is also the cause of the lowering inside hand. I don't see that dropping hand as a big problem in itself (I think that "banking" is unfairly maligned in high performance skiing), but because it is part of this rotation (note that it drops down and back), it is part of the problem. Notice that, as the inside hand drops down and back, the outside hand punches forward and "in," across your chest. The outside ski tail almost looks like it's tied directly to that outside hand--as the hand moves in, the tail moves out.
I believe that your upper body rotation also involves excessive forward leverage against your outside boot cuff, which further causes the ski tail to move out. This is also when the "a-frame" that others have mentioned increases. Although your skis carve very well throughout the turns, this is the classic syndrome of upper body rotation with forward leverage (pressure on the boot tongue, excessive pressure on the ski tip), causing an "abstem" (downhill ski tail stems out at the end of the turn) and an a-frame as you increase your edge angle to end your turns on a solid "platform."
My suggestion is to focus on maintaining a bit more "counter" throughout your turns, as well as playing with softening your edge angles a little earlier, seeking to finish turns with an edge release rather than an edge set. To eliminate the rotation (maintain counter), pay attention to your hands--drive both hands forward through the turns, but don't let the outside hand move ahead of the inside hand. And especially, don't let the outside hand reach in across your chest. Your turns should end--and begin, of course--with your upper body mimicing the lead of your skis--the inside half (uphill half at the end of the turn) will lead the outside half somewhat. In your videoed turns, your inside ski typically leads--very slightly, as the rotation of your shoulders and arms squares your pelvis--but your outside hand and shoulder lead. That's the rotation I'm referring to.
Do this right, and your turns will end with your body facing somewhere in the direction of the apex of your next turn, which is more-or-less the direction it should also be moving in the transition/crossover. As you complete your turns, your hands should be driving out of the turn--leading you across your skis and into the next turn--rather than rotating into the (old) turn and twisting uphill. This movement will also help release your edges in the transition. The result will be even cleaner carved turns, smoother transitions, and the ability to shape the bottoms of your turns more deliberately and accurately. (As it is, your turns have a necessary bit of "fish-hook" shape at the end, finishing with that harsh edge set, and you have no choice but to end each turn as soon as that edge hooks up and that outside hand hands comes around and across, whether you want to end it there or not.)
These changes will be subtle, although eliminating that chronic upper body rotation through the finish will change the character of your turns fundamentally. Because it is so fundamental, it will probably take a fair amount of practice to incorporate the change and get comfortable with it. (Remember, "if it doesn't feel strange, you didn't change"--the famous and oft-repeated words of Phil and Steve Mahre in their coaching program.) I'll be curious to see what else happens when you focus on these changes. I think you'll find that staying a little more centered in your boot cuffs--not so levered forward against the tongues, especially at the turn finish--will also help improve the carve and eliminate the widening/abstem. But I also think it will happen naturally, without needing specific focus, as you eliminate the rotation. Provided, of course, that your belief system gives you permission to get off those boot tongues. Experiment with it!
And have fun!