Welcome to the forum. I am sure one of the moderators will be moving this to your own "My Swing" thread, instead of having labeled under, "Need Analysis". Usually members create their own "My Swing" thread, just makes things organized.
On a side note, please learn how to embed videos. Its the little film icon. Just helps us so we don't have to keep bouncing between internet tabs.
Usually I don't after grips, but I would take a look at this thread. Looks like you are very palmy with the grip, and probably too weak of a grip.
Few thoughts on the posture, I would flare you feet out about 20-30 degrees. Helps free up your hips, just some freebie stuff with an easy adjustment. Just some information on posture. I think you could be a little more upright, little less knee bed.
With the knee bed, you need to loose some flex in your back knee in the backswing. Get that back hip to go back and up more. Maintaining the knee flex in the back knee is causing you issues, primarily a short backswing, loss of power, and keeping your heady steady. You do a good job with the steady head because of the shorter backswing. If you swung the club to parallel you'd probably have to shift your weight to the back foot more, which you don't want to do. Check out this video bellow for more information.