Cosmic Fusion does look like one esoteric alchemical book that seems quite irrelevant to common folks with a regular 9-5 job. But if one could strip away the mythical or metaphysical parts (like streaming in cosmic energy from the Big Dipper!), Mantak Chia's system does can benefit one's physical/mental health as well as help to promote one's spirituality. The followings are areas that I find very interesting (and Chia's meticulous presentation is certainly comprehensive and useful):
1. Opening the thrusting channels: the text explains the classic Taoist approach of clearing the thrusting channel up from the perineum to "below the heart", PLUS clearing it down through gulping-action of intense saliva swallowing. In addition, a modified Indian yoga approach of clearing the thrusting channels (plus opening the crown) through single nostril pranayama technique is also included. Very comprehensive.
2. Opening the belt channel: Again, the classic Taoist approach of tuning and strengthening the "circumference" of the lower dan tien is introduced. The text also extends the action to become a spiraling action on the whole trunk, under Indian yoga influence. Again, comprehensive.
3. The classic Taoist approach is an avoidance of driving chi to/across the heart (i.e. safer approach), with joining the heart energy and dan tien energy only through mind-directed meditation focusing on the area between the eye brows (or the third eye, as commonly being referred to). Chia also warns against driving too much chi to the heart.
4. Meditation to cultivate compassion: Ultimately Tao goes beyond good and bad, but cultivation of compassion is certainly an important middle station of a Taoist's spiritual practice. Here a Buddhist uses similar techniques as the Taoist. Nowadays, some Christians also use meditation to cultivate their morality (interested reader can refer to The Good Heart: A Buddhist Perspective on the Teachings of Jesus by Dalai Lama). Having said that it would be foolish to assume that one can cultivate one's compassion through meditation ALONE. To this spiritual end, one needs first to have a conscious determination to cultivate one's morality (be it religious or mere spiritual). Without such determination, one would likely to become "love thy neighbor as thyself" ONLY during one's meditation session! Needless to say, it will be useless and a waste of time if such kind heart can't be translated into real life (at worse, it would needlessly strengthen one's ego, be it kind or selfish!) Needless to say, Chia's method to strengthen one's compassion is just one of the possible methods.