Exactly. Try to tip the feet while standing up with a long leg - normally you can't do much, as the knees and ankles are not free to move - they're essentially both weighted down and "anchored" by the hips.
Then flex the legs (knee, ankle, hip to stay in balance) and try again: the more you flex, the better range of movement for foot/ankle tipping and edging the skis.
that's the classic joke with "bend ze knees, five dollars please"
2.
To relate it back to your video, as soon as your skis are flat, your legs get long right away, so you can't effectively tip - the only way to edge the skis is if you directly lower your hip (i.e. hip dump).
So, make sure the new outside leg - and by extension (sic!) your inside leg - doesn't go long right at the edge change, so that you have some range of motion for using the feet for edging.
1.
looking at your knees. you push them into the hill quite a lot - if the boots were aligned properly, you shouldn't really have to. For sure more tests should be done to determine what the issue is: you can simply to a straight run towards the camera, on one foot at a time, trying to maintain a flat ski and then see how the body alignment looks like - looks like you would have trouble even keeping a flat ski.
checking the cuff alignment takes like 2 minutes and it's well worth knowing if they're in the ball park.
cheers