Hey Mattias!
These are a great start man. You're certainly not too far off the mark! Narrow your stance 2-3" at the heels. You've got a decent amount of kyphosis, so I'm not sure how much flatter you're going to get your upper back, but it certainly doesn't hurt to try! Squeeze your chest up to the point of maximum discomfort. If you don't hate the way the starting position feels, you're probably not tight enough
Also, are these videos sped up or something? The frame rate is tripping me out, lol. Next time, you can just film with the camera in one spot from a front 45 degree angle. That's a better angle to see more than the side and rear anyways.