Yes, it takes some courage to post one's skiing up for the world to see and abuse. Rest easy, we have good people here who try to be as constructive and helpful as possible. Everyone has things they need to work on if they want to move their skiing to the next level. Those who have the courage to examine those technical issues and work on them are the ones who will experience the most success and discover new forms of enjoyment this sport has to offer.
Ok, on with my MA. The list of things you're working on are well chosen. Your upper body rotary (using an aggressive twisting of your upper body to turn your skis) is not too bad. I'm not too concerned with that aspect of your skiing right now. You do have some rotary issues showing up in the top half of your turns that can be seen in the interaction of your skis with the snow, born of a general rushing of your turn initiations, but I'll get back to that later.
In this video your lateral balance looks OK. I don't see any major inside ski overweighting problems here. This is a very important area in skiing. You do have some leaning in with the whole body, which may jump up to cause you problems when slopes get steeper and terrain gets tougher. And it will definately need to be changed when you want to start carving turns later down the road. These flatter slopes while steering turns is the best place to sort it out. There are a number of drills that can help. All of them strive to help you keep your torso vertical and your shoulders level to the snow as you turn. Legs tip, body remains upright, and an angle at the waist is created. To make it happen, try lifting your inside shoulder and hip as you tip your skis on edge to turn.
Completing your turns. This has to do with turn shape, and is where you need to place much of your focus right now. As I said before, your turns are starting too aggressively. There's too much tail push and rushing the first half of the turn happening right now, and you need to keep turning longer and more out of the falline through the bottom half of your turns. Because you're not currently turning far enough out of the falline, you're using a wide skid angle through the body of your turns to control your speed, and a rushed/pushed initiation of your turns to achieve that wide skid track. Try doing some turns where you see how subtly you can begin your turns, and how long you can delay reaching a point where your skis are pointing down the falline,,,, then keep turning through the bottom half of your turn until you're almost going uphill and you feel your speed beginning to taper off,,, then repeat a series of these smooth turns. You should feel a roller coaster senstation,,, speeding up through the top half of the turn, and slowing down through the bottom half. Make these turns big so you have much time to feel the entire process, then condense them into smaller versions of the same quality.
Hope that helps. No way to explain all this in text alone. Check out my website for more comprehensive learning options.