What about fitness....
 

You forgot completely about a fitness regime also.

Your machine will only be as good as your body allows it to be.

Strength, Flexability and Stamina....

Extremely important !

This includes weight training, cardiovascular training, stretching, diet (I don't care if your skinny - you still need one to maintain energy levels for four rounds) ...etc. Even simple stuff like skipping can improve your balance.... The more athletic you become, the better your technique will be and so will your ability to think clearly and execute time after time and the further you will hit the ball and the more innate good golf will become....

You very much need a holistic approach to playing golf - neglect an aspect such as this and you will never reach your full potential.