Alright so I'm here to help! Overall you have a very good start. You're horse is willing and calm. And you seem very confident.
Things to work on... Keep your legs back (have that straight line from ear, shoulder,elbow, heel), keep your heels down, and sit down on your butt. With all these things combined you will have not only better posture, but you will sit in the saddle and essentially not move from the saddle. Also when you land when jumping, sit back so that way you don't land on his/her neck. Like I said, you have a good beginning and with some improvements in some things, you will be golden!
Good luck with everything, hope I helped a little bit! PM me with any questions you may have.
~~Not many people switch from Barrel Racing to Western Pleasure. I LOVE pleasure but I still run!