a. I think you could start with your hips a bit lower but that is the least of your concerns
b. the major concern is this: your first movement is to shoot your ass straight up so that you're in an RDL/SLDL position; slow it down and watch what happens to your torso angle. It goes from angles to horizontal as you straighten your legs without the moving from the platform. Then you back lift the bar to about knee level and try to explode it up. That's not how you clean.
Rather, from the floor, the hips and shoulders should rise at the same speed (e.g. torso angle does not change) until the knees are close to straightening (th bar will be around knee level). At that point, you start to extend at the hip generating the double knee to scoop the bar into your lap and then explode.