Wing Woo Gar
Grandmaster
S
So your answer is no.Yi is not pointing a finger. Yi is the image of movement in your mind, which moves Chi. Yi is the decision to throw the ball into the glove of the receiver. Chi is the connection between your mind and your movement. It's the feeling of moving your arm and releasing the ball in such a way that the ball will end up in the glove. It's the feeling of punching "through your target" when in reality your fist does not pierce the other guy. The video in the OP explains, with all the visualizations, how Yi moves Chi which in turn moves your body.
This taps into subconscious movement, which everybody does, but it can be trained in specific ways to obtain different results. For example, there's a swordsmanship school in Japan that trains to cut in a way that deviates strikes, so no matter how or when the opponent strikes, he will miss and the adept will not. Through Yi/Chi, the adept makes a small spiral movement, and there's almost no impact. Watch the first few kata and listen to the swords.
Dunno about flying through the air. But it's possible to unbalance a noncompliant opponent through minimal contact. For no touch, I cannot think of many plausible hypotheses apart from exploiting the throwee's suggestibility, flinch, weight shift, and/or a combination of the three.