For your short radius turns, we need to teach you about dynamic carving. In the bumps you are demonstrating an excellent nose roll technique for turn initiations. When the bumps get super steep, this is a great thing to help start your turns. Once you get the board pivoted onto the new edge, we'd like to see you carve across the bump instead of side slip down it. But this a phase that many riders who are new to the bumps go through.
On the flatter terrain we can see the problem with this approach clearer.
This is you just before engaging your heel side edge.
This is you just after.
You get onto the new edge in your short radius turns by jamming your back foot out. Oh Lord if I could only have five cents for every turn made this way! This technique is easy to learn and it works, but it is not very efficient and not high performance. You are doing all the work instead of letting the board help you (or you are turning the board versus the board turning you).
In regular snowboard turns both feet go onto toe and heel side edge at mostly the same time and both legs bend and straighten at the same time and if a stick was dragged on the snow directly underneath your belly button, that line traced by the stick would stay pretty close to the tracks made by your board. The edging and flex/extend movements are mostly simultaneous (both feet/legs doing the same moves at the same time)
In dynamic turns, the path of the bell button takes much different path than the path of the board and the feet/leg movements are much more sequential (doing things one at a time) than simultaneous. The after photo above is a good starting point for imagining a dynamic turn. Your back leg is straight and your front leg is bent. In a dynamic turn, the back leg would begin to pass underneath the body (and shorten) as the front leg would travel out to the other side (and get longer). As the front leg goes out to the other side it is going onto to toe edge. At the same time the back foot is going to flat. After the back foot passes underneath the body, the back leg lengthens and the back foot starts to go on toe edge. But at this point, the front foot is already starting to come back to the body and the front foot is starting to flatten.
This isn't easy to do. The first thing is that you have to get your hips lower to the ground in order for the legs/board to get way out from under your body and still maintain contact with the snow. Then you have to really bend your legs to get them to pass under the hips without raising them off the snow. The second thing is that you need to work your weight forward and back along the length of the board at exactly the right time.
My favorite way to teach dynamic carving is to teach the "opposite" of the technique you are using. Instead of starting your turns with kicking the back foot to the outside of the new turn, finish your old turn by kicking the back foot to the inside of the new turn. This will stall your old turn out as the back foot gets more down the hill than the front foot. To come out of the stall, you must shift your weight forward aggressively. As the nose of the board start to turn down the hill as a result of this movement, add a strong tilt of the front foot onto the new edge. From here, just let the back foot follow through the turn and your weight will naturally recenter to prepare for the next turn. When you kick the back foot out for the next turn, you are actually shifting your weight to the rear foot. This sets you up for the next forward move to come out of the stall again. This introduces you to the sequential movement patterns that enable dynamic carving. From here, it's just a matter of smoothing out the stall motion and starting to lower your hips to the snow more.
This said, I've never found anyone able to do these kinds of turns from reading the Internet. Like I said, this isn't easy. Most people need some coaching in order to "get it". But once you do these kinds of short radius turns on a groomed trail it becomes obvious how useful these turns are in the bumps. In the bumps, skiers use both legs at the same as shock absorbers. In the bumps, riders need to use one leg at a time to get the best shock absorber performance. Think of this way: as you travel over the top of a bump the front foot comes up the hip while the back foot extends down to the bottom of the trough, then back leg shrinks as it comes up to the top of the bump and the front leg lengthens as it goes down into the trough.
You've already got some of the moves to do this. As seen in the after picture above, you've got some of the sequential leg movements. And in the carving heel side turn you are getting your feet way out from underneath the body. Good luck in your quest for higher performance riding. I hope this helped.