Is the Bindu point at the beginning or the end of the training?

Thank you for the good question!

But towards the end of your pdf I can't quite make it out, but it seems like your saying intention should fully be placed on the bindu which by itself begins the whole process. 

I recommend this website http://qianfengdaoismuk.weebly.com/ for further training details.
Yes the beginning of the Taoist Yoga book says to focus on the center of the brain until the light is bright - from the heart - and this means that the yin qi has been replenished, so that the small universe can be opened up for real. But to do this requires that the heart intention be pure, such that the shen naturally goes down the front, instead of the shen going out of the eyes, via "Evil Fire" of the heart. And so this is much easier to do at a younger age when a person is pure of heart, and since any older person is usually not pure of heart, then the small universe is used to purify the energy. So then if chapter 1 can not be done, then the small universe is used with the Quick Fire or Warrior breathing - which has the power to sublimate the water, to get it above the fire. In the above website, the author of the book, emphasizes, that he taught that with standing active exercise, the results are achieved twice as fast, when combined with the sitting meditation. This is not mentioned in the Taoist Yoga book directly though.

But the main point being that I am against the "meme" of "semen retention" because as qigong master Effie P. Chow teaches - the healing is all about the intention - and the goal is to increase and retain the qi energy. "Generative Fluid" means an impure heart - and so if your mind's goal is to retain "generative fluid" then you have negated the goal if increasing and retaining qi from the get go! This is the subtle power of the Mind as Shen, that the Westernization of the training has lost - and so only a "lower path" is allowed. Taoist Yoga recognizes this "lower path" stating it can be used for health but that is all.

So then to even get to replenishing the yin qi to that of a 16 year old is very difficult and 90% of people training do not make it - that is my estimation. And then those few who do activate the Yuan Qi, as Master Nan, Huai-Chin states, achieve spiritual capabilities, use those capabilities, and so then "fall back into worldliness" due to "heroic overexuberance." This is what happened to me. So then I have had to go back and study the book Taoist Yoga: Alchemy and Immortality even more - and so I recommend the "word searchable" format or "full text" format in archive.org - since that enables a better means to "connect the dots" of that book, since so many terms are used that cross correlate, with so many details that can be discounted, etc.

So when the Yuan Qi is activated - that means all three tan-t'iens open up into the 5th dimension as nondualism - and so the third eye opens up - but as that above website link states, the ancestral cavity is inside the body and yet the mysterious gate is outside the body - or as I have it quoted on my blog -

It can be said that the ancestral cavity is the mysterious entrance that humanity must pass through during self-cultivation, but the mysterious entrance is not inside the body, and the ancestral cavity is not outside the body.  When the disposition of fire does not flare, then the dragon can be controlled and possessed. One can then obtain the time of lead. Therefore it is said: “If you don’t amass mercury, how can you seek lead? If you don’t subdue the dragon, how can you tame its tiger?” Xing ming gui zhi, 1615