I like the edge engagement (vs skidding) and your solid balance over the board (e.g. not sitting over the back foot). I also like how your toe side turns have just a slight amount of back arch instead of bending forward at the waist. Your 180 toe to toe turns land nicely on the new edge (try launching them with a bit more ollie). It's time to step up your game to more difficult terrain. Focusing on retraction turns is the right preparation for moving to the next level.
Arm movements are usually symptoms of lack of other movements vs a cause of riding issues. When you ride holding the camera on pole, can you see how the back arm is much quieter? But you also kick the back leg around more too. Try riding with your hands held together behind your back. If that is hard to do, then you need to work on leg bend drills. My favorite one of those is to ride with your hands on your knees all the time, except for a brief moment when you want to start a new turn. Raise the hands to touch your shoulders, change edges, then go right back to holding the knees. When you can do that, hold the top of the boots. When you can do that, hold your toes. When you do that, do a grab on heel sides and touch the top sheet on toes sides (and yes keep rising to touch your shoulders for edge changes). When you can ride easily holding your hands together behind your back, then you can focus on choosing a riding style where your hands cover the tip and tail or your hands mimic holding a steering wheel. Either way, from there try holding your shoulders in line with the board at all times as a drill (especially heel side). If you are using constant leg extension and retraction movement throughout your turns (as opposed to just retracting to start your turns), this should be easy. There are different styles of riding that include some amount of shoulder alignment different than board alignment. The slight differences in board vs shoulder alignment I see in your riding aren't a bad thing, but you should be aware of what you're doing in different parts of the turns and the plusses and minuses of getting out of alignment at each point. Make a conscious choice instead of an accidental one. This effort will help make retraction turns easier. I often tell my students "You turn with your feet, not your shoulders". But you can't turn as well with your feet if you are not using leg retraction and extension movements while you are trying to steer. If you focus on leg movements while you are turning, you will find that you need to use less shoulder movement and that the position of your hands therefore becomes irrelevant.
At 2:22 we can see an effort to do retraction turns. In instructor speak we call these dynamic carving. This is where the path of the body and the path of the board start to noticeably diverge (e.g. the path of the body is much straighter down the hill than the path of the board making "S" shaped turns). Something else starts to happen too. The leg and edge movements start to become sequential instead of simultaneous. So instead of both feet shifting onto the new edge at about the same time, the front foot goes to flat while the back foot is still on edge and then the front foot goes to the new edge while the back foot goes flat. When the front foot goes flat, it is directly underneath the hips and the front leg is at the shortest length. At that time the back leg is at it's longest length and the farthest distance away from the body. After passing underneath the body, as the front leg starts to lengthen, the back leg starts to shorten (retract) as it begins to pass underneath the body. In your turns, I see the beginnings of picking up this technique. But there are a few things holding you back. The first is that you need to get your hips lower so that they can stay at a constant height off the snow. Currently you have some "bounce" in the hips that is making balance more difficult and slowing the retraction/extension leg movements. We want the upper body to be stable vertically. The legs should be extending out from and retracting back to the same point. The next thing is to add some forward and backward weight movement along the length of the board. As the board starts to get out from underneath you, your center of balance should be shifting backwards slightly. As the board starts to come back, your center of balance should be shifting forward. One way to think of this that it is a result of board movement. But if you practice consciously shifting your weight forward and back, it will help you. The last thing is board twist. You're not using it as much as you need to for retraction turns.
For weight shift and board twist, my favorite drill is "the stall". You can often see intermediate riders start their turns by kicking the back foot out to the outside of the new turn. For this drill, I want you to do the opposite: finish your turns with a kick of the back foot DOWN the hill. This will cause you to skid and stall out (almost come to a stop). It also causes your weight to shift backwards. To come out of the stall, you need to step hard onto the front foot. That's the weight shift forward. As you do that, step only the front foot onto the new edge. That causes the board to twist along the length of the board. It helps you get the front of the board onto the new edge quicker and with more stability. As this move becomes comfortable, make the stall move more and more subtle and your turns straighter down the fall line (less movement back and forth across the hill) until only your legs move side to side while everything hips and above moves straight down the slope. Once you get the hang of this drill, you'll see how similar it is to riding in the bumps. The transition from this drill to riding the steeps and bumps should be pretty easy. Then you'll need to start planning some trips outside of the Mid-Atlantic to really test yourself. Have you been to Jackson Hole yet? Don't forget to send us the video!
Does this help?