Allow me to clarify. Yes, the exercises are neutral, in and of themselves, effective relative to the practitioner. I was speaking of my personal experience and practice.
I learned the exercises at one of Master Lin's clinics. I got to experience what he was like. I found him a very positive teacher, with the highest intentions. He worked(energy/healing) on people taking the clinic, as they did the exercises. His energy was felt in a positive way, and enhanced the experience. I have experienced this before in the presence of good teachers. He was great to be around. If I put on a tape that has him speaking on it and making the tones/sounds for the meditation, it enhances the exercise for "me", as I reconnect to something positive that I experienced in the clinic. I also realize a connection to the teacher's teachers. Even if I have learned something out of a book, I acknowledge a connection to the writer/teacher, if I learned something, and I am utilizing it in my practice. And again, his or her teachers. Knowledge/wisdom is passed down from teacher to student through generations. I find, personally, that my practice is enhanced if I acknowledge where something came from, pay respects, give thanks, and ask for help/energy to do what I am trying to achieve. This is a personal choice.
Regarding standing like a tree. Although I am not familiar with this particular exercise, it sounds familiar to a myriad of static postures that do similar things "in general" regarding qigong exercise. Some might additionally focus on a strong stance and grounding, some might focus more on taking in energy from above. Various positions involve a circular arm held position, Golden Circle, "embracing a tree", etc.High horse, low horse.... Some build a strong "bridge" in the arms for martial arts, all usually address general health. They are all effective. Some more balanced than others. I find that the forming of yin and yang exercise has the same feeling, for me, as some of the above mentioned exercises. It is a nice , very balanced posture that generates alot of energy in the whole body. It's reference to opposites, both in posture (one hand up, and one down), make it very powerful and simple. The forming of yin and yang is a powerful concept. In the moving of yin and yang, you can continue the powerful feeling of what a solid static posture does, if you move very slowly and keep your movement full and open. Perhaps someone who knows the specific exercise you speak of can give you a better answer. I am assuming what it is by its name. Something connected to the earth, and receiving energy from above. :-)
