You shouldn't be staring at all, really. You're watching the hands in the sense of keeping track of them with your peripheral vision. A defuse stare that allows you to utilize your peripheral vision, focused at about his chest level, will allow you to keep track of what you need to see.
His hands are more of a danger because they are what humans use to hold weapons. Any movement of the hands is also going to be associated with shoulder movement and elbow movement.
You won't be able to "read anyone's intentions". At best, you can make an educated guess. Physical motions that correlate to your movement and aggressive motions that signal an attack are what you should be looking for in the aggressor's pattern of motion.
His hands are more of a danger because they are what humans use to hold weapons. Any movement of the hands is also going to be associated with shoulder movement and elbow movement.
You won't be able to "read anyone's intentions". At best, you can make an educated guess. Physical motions that correlate to your movement and aggressive motions that signal an attack are what you should be looking for in the aggressor's pattern of motion.