You should practice jump transitions first as the kite movement is exactly the same for a backroll transition or double/triple backroll transition. Seeing your video I'd also like to suggest you practice not looking at the kite. Feel the kite.
So tips on the backroll transition for entry level:
Front hand is not even needed. Make some mental notes to remember which hand to put pressure on (back hand) before you go into the spin. Come in at moderate speed while sending the kite to 12 slowly. You will feel tention building in the lines and should be able to feel when it reaches 12. Keep your back hand near the middle of the bar. When the kite reaches 12 exactly (before and after 12 is a problem while learning the basic move) sheet in and pop off the water into a spin keeping the kite at 12. The aim is to transfer all your speed and line tention into a stationary lift. Once you complete 3/4 of the spin look at the water to spot your landing and send the kite into the powerzone agressively at this time unless you are more than 2 feet in the air. Point the board with the front foot for the landing and land with more back foot pressure (exactly the same as a normal jump). Sheet out and send the kite back towards 12 to regain power. You should be riding off in the new direction now!
Stationary Jump and spin while kite is at 12.
Redirect the kite hard just before landing (sheeted in with power) Looks similar to a water start dive for the current conditions.
You need to kill all forward momentum and transfer that enery into lift when you sheet in.
Later you may want to remove your front hand all together. Feels great!
Heres a short clip from the other day. http://vimeo.com/59779113
Good luck! Keep at it.