I would like to see you put a towel just past the foul line and lift the ball just over it with your fingers. The ball is coming off your hand a little too quick and should be on your fingers a bit longer, the towel drill should help.
I personally don't see a problem with your footwork. You have long arms in relation to your legs, so your swing will take longer than most which is why your feet don't need to be as quick going into the slide. If you count the pace of your foot work it goes 1..2..3..4..slide even paced the whole way, no slowing or speeding up except in the last shot for some reason you quickened into the slide a bit, you didn't make a good shot, so I would assume that it felt awkward and not right.
If you increase your revrate by doing the towel drill I described above and you then need to increase your ball speed you may need to start the ball a bit sooner to allow your feet to be able to build up speed and quicken into the slide and be in proper timing so your foot gets to the line just ahead of the ball, but increase the revrate first, speed with not enough revs is a recipe for low scores.