Wish my wife could board like that but oh well. Looks good and you have come along way dont worry about getting a new board you need to feel confident. Like you pointed out you open your shoulder when you turn toe side, what works for me on moguls is to point where I want to go so your shoulder is pointed and your body lines up. Not a crazy point but a more just a casual in front of your board point. Also you look like you are treading water with your hands being so high all the time, if they keep coming up hold your pants till you get used to keeping them down. Over all for what knee problem you have you look very good, dont worry about sliding on the black it looked like a slush day.