Hi Norman. I liked how you understood some use of flexion in anticipation of the shape of the terrain by your first two videos. Your upper legs stay in a good position but the upper body bends too much at the waist and is really the only difference between the two. I like your stance more in the first than the second. You are not using your ankles enough to aid your balance. Let's get you in balance by using parts closer to the snow .
You have many things to work on ,like most of us but the one thought I would like you to consider is to get the movement(Flexion of the spine at the hip)in the boot instead of the hip. Flex and open your ankle just like you flex your upper body but now keep the upper body quiet yet focused ahead.
Flex the ankle under your body in anticipation by of the rise and open the ankle to keep the skis in contact down the side. This will keep you in balance by having your feet under you at the crest and it leaves you a good range of movement when the hills falls away. Allow the knee to work with the ankles to make your suspension more functional. Let the legs do their work. Make it less work by staying taller and using the lower legs more to aid your balance
Practice just like you saw of the skiers playing on that spine. First try to keep your head level by using your lower body to absorb some small bumps. Then allow a bit of rise to keep the upper legs quieter yet leaving range of movement to extend down the side. If you had such a spine I'd work it over and over again until you feel comfortable and in harmony with the terrain.
Reach with your toes, bring them back under you as you crest the next. Hands in front. Think tall.
After you smooth out the ride let's find new stuff to think about.