I actually think youir horse will show better over larger fences, he appears to just be stepping over these without making a lot of effort.
In term of your equitation, I like kaykat's analysis above.
You don't mention what circuit you're showing, but I have to caution you - kimberwickes are unconventional in USEF hunters, and in a show run according to USEF rules, you'll be penalized for using one. In AQHA shows, they're pretty common and will not be penalized. Even if it's an AQHA show, consider getting him a bit that fits a little better - this one is too large for his mouth, and it calls even more attention to it.