Max, looking at the video you posted, I was more interested in watching you than Harald. Has anyone suggested that your poles may be too long for you? When Harald turns, his pole touch is fairly close to his body, his forward progress continues smoothly and his body is usually balanced nicely over his downhill ski. In contrast, your touch is further down the hill, making you "reach" further than perhaps you need, which subsequently pulls you out of balance. Your actual pole touch, because the poles seem to be too long, appear to jar you and throw you back, interrupting your forward flow. The hand you touch with then tends to drop back behind you, creating an upper-body rotation that I know you don't want. This puts your weight onto your uphill ski, forcing you to do more than you want to in the transition to recover back to your downhill foot.
What do you think?