Really the biggest issue is just the lack of a strong drive. I am using figures from slow mo video at about 9 seconds you are in a good spot although not much load on leg (could be angle having a side view from other side would be helpful.) at about 10 when you start your drive there is not much push off you are more just kind of collapsing and rolling over that back leg. It is fine to rotational with back leg but yours is just not very explosive which is what we want to really create seperation and increase velocity. I think your mechanics are in a good spot so that as you get more athletic and strong you should see a nice increase in velocity. The one note I would say to work on is try to keep your weight back on that back leg a little more. This is a drill you can try so you get more of a feeling of sitting then driving.
If you have any other questions feel free to shoot me a pm. I would be more then happy to give you some tips on lifting and what not.