How active should the legs be in the downswing and the followthrough? And how early should the left leg be straight?
The legs compliment the golf swing. I never believed they played a huge roll in controlling the golf ball. Now, if you are looking for power maybe. As the right arm begins to straighten out in the downswing the club needs a place to swing to. If you can turn your left hip out of the way this will provide a place for the arms to swing to. I am not a big fan of a stiff left leg...Straight or slightly bent is ok