The slowing down is something we have shown recently as well.
My daughter has always been told arm speed, arm speed, arm speed. As explained to us, if the explosive energy is being used in the upswing or beginning of the circle, you can only slow down going into the release or snap. She has been told instead to have a more relaxed circle and explode at the bottom to create more snap.
I am not sold yet, but it is one of the many new things we are trying.
I know its tuff when we as parents are not the so called expert and depend on the hard earned money we spend on a professional to give us sound advice. We try and educate ourselves so we have a better understanding and then confusion sets in. I have really started to lean on the great people of this website to get straight and honest comments and feedback to make sure I guide my DD in the right direction.