Hey dude - well I watched both attempts that you posted. While the crouched position isn't really necessary on the approach, since you're getting the proper take-off (in a tall position), I wouldn't change it. Also, while shortening the rope will indeed decrease the width of the wake, it also affects your approach speed. So again, I wouldn't change that either. In both your videos, you are letting go of the handle with your back hand and straightening out your body. You need to land with BOTH hands on the handle. In the first, where you come up a little short, both hands on the handle would give you a much more stable position to try to ride out the landing. In the second, where you clear the wake, you let go (and straightened-out) so early that you under-rotated and caught your edge.
So, keep both hands on the handle! This is how you control the rotation of the trick. By letting-out the handle, you'll slow your rotation and conversely, by pulling-in on the handle you'll speed up your rotation. Either way, landing with both hands will give you a much better chance at riding out the landing.
At first, you probably won't have the awareness of whether you're under-rotating or over-rotating. But, with both hands on the handle, the tendency is to over-rotate. This is probably better because the landings (crashes) aren't that hard, you simply skim out. Eventually, when you start to see the landing (the water), you can extend you legs to stop the rotation and 'touch down' on the water. BUT, keep both hands on the handle.
When you really get them dialed and go huge, you'll find yourself effortlessly controlling the rotation by using the handle.
Have fun & good luck!