Greetings Audi,
Thanks for patiently answering my questions.
Firstly, you explained:
<When you use the four primary techniques(Ward-off, Roll back, Press and Push) you tend to bring the opponents energy in to your center and then redirect it out. As you bring the opponents energy in you may have difficulty using Hua to return it back to the opponent and thereby lose your stability.
When you do the four secondary techniques, you usually do not bring the opponents energy inward in the same way. With Cai and Lie, you usually are directing the opponents energy away from you and do not need to bring it inward so much. With Zhou and Kao, your opponent's energy is already inside some of your defenses and will probably be cut off by your application of energy. These energies do of course have their own disadvantages; but the stability of your root is, I believe less of an issue> Audi
That is a very logical answer. Understandable and helpful. That might have gone unnoticed by my perception for a long time without clarification. Thank-you.
You pointed out:
<As for your list of energies, I would have to say this reflects more Zhang Yun's views than what I understand of the Yang's teachings> Audi
Thanks for making that distinction for me. I myself am not qualified to distinguish the differences between traditional and modern viewpoints in Taijiquan aspects and texts, and appreciate the gesture.
Yes, the list I provided was a ninety-ten split with Zhang Yun text prevailing......actually, better make that a seventy-thirty split.

The idea was to gather information in one spot to use as a platform for inspecting the subject of shi san shi...something to correct, question, add, subtract to, etc.
Something to be modified as the thoughts and sources appearing on the thread progress.
It was good of you to provide an example of the order of training for Yang style Taijiquan. Pretty much what I had expected...moreover, it seems to make logical sense.
Lastly you said:
<By the way, "tsi"should be spelled "ji", in order to be consistent with the transliteration scheme used in the rest of your post> Audi
"By the way"...was that intentional? Ha, Ha, Ha, Ha! Witty, Audi, that tickled

Thanks for the Tsi/Ji distinction, I will correct that in my post. Is that due to different dialect, Family style, other?
Nice day,
Best regards,
Psalchemist.