I'm not saying that the head must always be horizontal, only that it follows the angle of the spine. If this was what you meant, then we agree, but because I can't see you, I’m not sure.
Luckily, I have Wolfe Lowenthal's book at my desk this week. I had a look, but it's hard to tell what his spine is doing, so I found some other pictures to compare. These are from one of the Italian YCF centers-I found it on the Dong Yinjie topic. http://www.taichiyangfamily.it/albumfotografico.htm
If you look at Master Yang Jun in Snake Creeps Down, you see his head in line with his spine. Also, in the picture of Master Yang Zhen Duo shaking hands (I don’t know who the other man is) it’s very clear that his head is in line with his spine even though he is bent forward at the waist.
I’m not sure about the third gate, but I think that generally, keeping the head top suspended stretches out the small spaces between the vertebrae, thus allowing for greater chi flow along the spine and into the head.
Yes, looking down can help the energy go down when that is where we want it to go. This is great for Punch to the Knee, Punch to the Groin, Snake Creeps Down, Needle at the Sea Bottom, and whatever else I forgot. But in Yang style, as I understand it, we’re not specifically thinking about Ren Mai, Du Mai, or the Microcosmic Orbit.
An additional thing my teacher mentioned in class recently is to avoid tilting the head from side to side as though dancing to internal music. It’s good to feel the chi moving, but not allow it to dictate the movement. The mind should lead and this focus can keep the head steady.
I think it’s good not to have to rely on seeing the opponent—but if you can see him, why not train to look there? Personally, I enjoy pushing with my eyes closed from time to time to see if I can still maintain balance, anticipate my opponent’s moves, and sometimes to better focus by tuning out extraneous visual input or to examine what’s going on inside. However, I must note that this goes expressly against what my teacher says to do. He insists that we keep our eyes open to be aware of what’s happening in the world. I think his is very sound advice…but I’m the kind of student who has to test everything to see if it’s true…either that or stubborn