Qi Gong is the mastery of the mind, body, and spirit with breath work. The focusing the mind and breath while the body is in a static posture, such as meditation, or body movements allows the body to replenish the internal Ch'i. Nei Gong is considered more of an internal exercise. It allows the body to move in a continuously stretching, expanding, contracting, opening and closing motion. It provides a holistic connection between the mind and body through breath work and body movement.
Tibetan attitude is quite different from other Chinese traditional beliefs.
There are really no right or wrong. It's more the attitude of honoring your self, your mind and body. All exercises are done without exerting any extra effort or going beyond your capability. The Qi Gong and Meditation exercises are done comfortably and what feels right for you. Work with quality rather than seeing how much effort and maximize the activity to be better.