I think that the seat looks fine to almost a tad high. I paused it while his leg was at the greatest extention and it seems ok. I can't tell because of the loose shorts but it looks like the hips rotate just a tad bit. If not, it's because you are rocking left and right. It does look like you could use a longer stem or flip it. I definitely agree with the knees bowing out. Keep your body in tighter to be improve aerodynamics