Ross May 24, 2016
Q1 No, not necessarily. It turns for some golfers and some hold it. It can be used to help keep your weight forward, for those that slide, or let their back leg move laterally.
Q2 Ideally, the start of the downswing is an “entire” unwinding move (like throwing a ball). You don’t have to think about what starts is and the body unwinds from ground up. If, you struggle with starting the downswing, “The Finish Drill” will help teach the feeling of how the “hips” work at the start. Now, for a right hander, the front (left) hip should feel like someone is pulling your left hip belt loop and spinning you around… but I’m not saying the “left hip” does anything alone… the hips/body all unwind together like a rubber band unwinding (if the backswing was wound up correctly).
Q3 Yes, they play a very big part. Again, do the “Finish Drill” and learn which of your muscles fire to accomplish that drill.
Q4 This is not a quick answer and can have many different reasons, BUT in general, a typical correct finish (any golf swing any method), will have almost ALL your weight on the outside of your front foot, with the front foot sole slightly off the ground. Very little weight is on the toe of the back foot at this point just for balance. I would have to see your specific reason for not completing your downswing. Some golfers have to modify their setup (flare out front foot at setup), to allow them to rotate to the finish of the front foot. The “Roll your Feet” video can show you a little more how the front foot should look at the finish.
Q5 I don’t think age has anything to do with it. Sometimes physical limitations play a part, but there are some adjustments that can be made to help allow the turn to complete.