Greetings Heng Yu,
Thanks for your thorough reply to my questions, I appreciate it.

You wrote:
<That kind of depends upon why you practice Taijiquan in the first place; to ignore the mind whilst training the body will not lead to the highest levels> Heng Yu
Hmmm...judging by that response, I deduce I must have given the wrong impression...
If anything, the correlation between the psychological and physical aspects in Taijiquan is of primary, utmost interest, importance to me in my studies.
Firstly,
You wrote:
<The first level of unification is purely physical. When the musculature is free of habitual tension, the body weight will naturally fall, via the aligned posture, into the floor.> Heng Yu
Yes...INTO...the floor. A distinct sensation, that is, and an elusive task to achieve, for me. I have my moments, but nothing consistent or under my command yet in that domaine. I do know what you're referring to, though. Nicely described.
You continued to describe the effects...
Physical:
1)Rootedness
2)The practitioner is able to glide with ease in any direction with the force of an iron ball.
Psychological:
1)Calms the mind to an incredible degree.
Which in turn leads to
2)Unification of the mind and body.
<A calm mind percieves more. When the mind is not taken up solely with intellectual activity, the true spectrum of awareness comes to the fore...The body is permeated by awareness.> Heng Yu
I am now clear on your use of the term "unified existance"...Thenks for your explanations.
The awareness you speak of I have seen illustrated (even tried myself) in experiments with blindfold and opponent. When there is existance of such awareness, one need not see the opponent to know where he is, or his intention. There is no thought involved it is purely "feel" and "awareness"...That's one really fun way to test out ones awareness, to see how honed it is.
When a practitioner is faced with multiple partners , I have heard that he should not focus his vision on any one opponent in particular, but rather "feel" for all of them.
Looking detracts from "feeling" and "awareness"...apparently.
If one is song then one becomes rooted. This I understand, but I have never heard any previous allusions to "...with the force of an iron ball"...May I ask what source that imagery was drawn from?
Although I am versed in the concepts of awareness, or unified existance, I am still uncertain as to your reference to 'striking fear, confusion and panic into an opponent' with it's prevalence...Slight disconcertedness, perhaps...???
Lastly, you wrote:
The relaxing of the tension is achieved with the dropping of the breath and the opening of the Qi channels> Heng Yu
Can I assume you portend towards sinking the Qi to the cinnabar field, the Tantien point, when you say "dropping the breath"?
And
Donning correct posture, proper alignment, when you say "opening the Qi channels"?
Thank you,
Best regards,
Psalchemist.