I believe that if you can get your chin up off your chest at the takeoff, you will open up the chest more and have a quicker swing to the top. Everything else looks pretty great!
I really like rope drills for working on the top end, because it simulates the vertical pole at the end of the vault better than rings or a highbar. Ideally it is a long gymnastic rope with a semi-padded floor, but just a clear area is fine. The key is that these drills force you to "get tight" at the top and pull through your top arm to stay in line with the rope, just like you should on the pole.
-hanging swing-ups: reach your top hand as high as you can on the rope, so that your trail leg is just off the ground. Grab the rope with your left hand with the rope running across your forearm/elbow so that the bottom of the rope is shifted out of your way. Swing up and invert up the rope, several times in a row. Do 3 sets. Video of this drill and some other good ones:
http://youtu.be/gUnPwGOzk44-running rope catch/swing: Take a few strides, run and jump up to the rope, catching it as high as possible with your top hand. As you "catch" your hands on the rope, your swing will begin. Accelerate the natural swing up to inversion on the swinging rope. It's ok to grab the rope with your feet at the top of the swing if you need to. Hang on and stay tight! Great video of this drill at the beginning of this clip:
http://youtu.be/spJi5KMvyzkGood luck,
Tom