PGA Pros know the exact distance that they hit each club and you should as well, go out to the range when it is soft and hit each club in your bag squarly and mark each distance so you never select the wrong club again
Proper impact is by far the most important part of the golf swing, you must make contact with the ball and the ground at the same time with a square clubface in order to maximize your distance and accuracy
Hitting the sweet spot of your putter face is essential to being a great putter because the putter head will not twist or turn if you make the perfect contact