Only took a quick look at one of the videos. Not bad at all.
Your tossing hand should continue upward after the ball release. you tend to stop it right away and/or pull it down too quickly. Take a look at the pros. After the ball release, the tossing hand keeps moving upward so that the arm assumes a vertical position. This gets your front shoulder higher for a better shoulder tilt for your trophy position.
The extended hand also provides a better reference (measuring too) for your toss. It helps you to better determine the quality and location of your toss. It should also provide a better indication for when you should swing at the ball. Do not pull your extended arm down until your racket head drops from the trophy position down to the scratch position.