Go out on YouTube and type in USEF Hunters+flat and see if youi can get some results of USEF hunters. (Using Hunter Under Saddle invariably brings up lots of AQHA and other breed classes.) They're hard to find, but they're there.
The first thing you will notice is the difference in head set. I can tell from a photo at a glance if a horse is a USEF hunter or a breed show hunter because the head set is a dead giveaway.
The good news about your video is that your horse's head and neck has come UP from the typical AQHA hunter head set. The bad news is that it still needs to come OUT. Your horse is carrying too much flexion at the poll, and not enough contact with the bit.
I think you'll find you and your horse will initially do better in the over fences and the eq over fences; more skills will transfer from one ring to the other. To pin in the flat or the eq on the flat, it's a little more idiosyncratic - your horse needs to move and carry itself more like the other horses in the class.
This is the first vid I found, and it's not great, not an A show, but it will give you a better idea of the expected way of going, at least - http://www.youtube.com/watch?feature...&v=uRx1yNl2u5Y
And here's a couple of pony classes from various years of Pony Finals. http://www.youtube.com/watch?feature...&v=YKIr5c3zG24