Have I got a flexed right knee, and do I shift my weight on the backswing?

Your right knee probably over rotates a tad to much but it's ok, and the flex is ok aswell. You could shift a bit more weight onto your right foot, it does not not look your shifting all that you possibly could.

Also I noticed your losing your grip a bit at the top of your backswing, not sure how to fix this but try keeping your pressure points firmly on the club withough over gripping it.

Your follow through begins to soon after inpact and looks a bit lose, you probably could shorten it and have more control. A trick I got tought is stand still with you right hand out in front of you with you thumb up like your going to shake someones hands(keep golf posature and stance), then just turn you shoulders/hips to the your left like you turning around to shake someone elses hands on your left.

Anyway I am no expert at this so I may be wrong with all this, if I am just ignore me

Could well be right with the grip, I always find that a problem, I know where my hands should be but ...