1) The document provides instructions for various badminton shots and techniques, including grips, serves, clears, drops, smashes, drives, net drops, and lobs.
2) The key elements for shots are good body position, making contact with the shuttle in front of the body and as high as possible, and using strong wrist movement.
3) Common mistakes discussed include incorrect grips, contacting the shuttle too low or behind the body, insufficient power from the wrist, and shots that do not go deep into the opponent's court.