Keeping your right elbow tucked in during the downswing leads to the common problem of flipping your wrists
Have a 90 degree angle when turning the shoulders, bending the right arm and cocking the wrist for a balanced backswing
A backswing that is too long may feel like it is creating more power but it is destroying your fundamentals, grab a range bucket with both hands and swing it as far back as you can go, that should be where your backswing ends