Your fast feet at the end of the approach, falling off the shot, and other items of concern can be contributed to very early timing. This means the bowling ball is ahead of your feet during your approach. Take a look at the following two still images I pulled from the video.
The above image is your second step. With a 5 step approach, the ball should be in the pushaway zone during the second step. Here you can see its in the start of the downswing. The first thing I would work with you on is keeping the ball above waist high at this point in the approach, then letting the ball fall into the swing during the next step.
Just to reiterate how early your current timing is, this is your third step in the approach. The ball has reached the top of the backswing while you have two more steps to go. Your arm is bent because you have to hold it up there during the next two steps. And your feet are fast also because you have to complete two steps during the forward downswing to the release which generally takes 1 step.