Area 2- How I keep others from applying force to me.
To keep a force from being applied to you it's necessary to deny it a "resting" place within your body. So if someone is applying a push to your shoulder trying to stop the push at your shoulder will provide your partner with a point of application, a resting place, for the applied force. You need to let the force of the push flow through the shoulder and either ground it, redirect it, disperse it or cycle it around and return it to your partner. Alignment grounds, perpendicular forces redirect, angles disperse and capacitance cycles.
The same four principles are applicable whether you are stationary or in motion.