Well, firstly I'd ideally get confirmation from the regular circle of pros who post here that these are your priorities. And if you're signing up for evolvr soon (I'd recommend that), you won't need this thread anymore.
Thanks for the comments. I've always wondered a little about my left arm, and the way it flexes a little at the top of my backswing, but never considered the right arm too much. Reducing the flex in the right arm will probably do the same with the left, but I'm not sure what benefit this will bring to my swing. I'm not saying you're wrong at all, but I always like to know why I'm doing something. You also mention my arms in point 3, and I do wonder a little if perhaps straighter arms will give more consistency to the low point of my swing and get rid of occasional thins and fats.
You are on the right track here.
Over-flexing your right arm beyond 90 degrees can shorten the arc too much and thus reduces the amount of speed and power you can generate. Mostly though it can make your low-point too erratic and more difficult to predict, especially on the follow-through.
Check out this quick video for another explanation, which follows along the lines of what you were saying in the bolded quote above.
Continue to bank your right foot, yea. It just appears like your right knee is collapsing inward too much and not extending and straightening enough through impact.
This tip here is the one that I'm not sure off. I'd be interested to see what Mike, James, or Erik has to say about my recommendation of this piece and whether or not I'm on the right track.