Man you say you're 11 and 4'10", and you are using this program to increase your vert? Why? I don't think you will destroy any muscle like another poster mentioned, and I doubt you'll stunt your growth. However, I don't really think there is any reason for you to be doing this at your age. I really don't like it when people discriminate based on age, but this is just logic and physiology here. I didn't get my first growth spurt until I was almost 16, and then I got a second growth spurt when I was 19. I've been playing ball since elementary school through college, and I didnt seriously work on my vertical leap until my sophomore year of high school. When I was a HS sophomore I was 6'3" or so, and now I'm 6'7".
Aren't there other more crucial skills you could be working on?