As you can see, life is keeping me occupied and putting me behind in keeping up with the classes. I just did # 7 two and a half times. It is one of the hardest classes for me because of my weak ankles( which are getting a little stronger so that I can do Golden Rooster on my left leg for 3 seconds and right leg for 2 seconds). I do your classes at least twice. My question which I have been wanting to ask ever since you started the punches(I don't know if someone else has asked this), I recall at Lan Su when we were practicing "downward, parry and punch" that you demonstrated coming forward with your right hand in a horizontal fist and ending up in a vertical fist. I recall you saying punching with a vertical fist is better. So I got confused in doing these punches and reaching out with the flat hands and turning the hands into a horizontal fist.
A vertical fist is used when hitting the side of the body or the side of the face because it gets your fingers out of the way and you are less likely to break you own hand. Several traditional martial arts use this fist because they fight with bare knuckles.
The twisting motion in a jab or cross as done in the video will add to the power of the technique but are more likely to injure your hand. Boxers, YiQuan practitioners and MMA fighter that use this type of punch wear gloves.