Several points need clarification here:
Taijiquan is a very formidable self-defense system. The techniques in taijiquan cause much greater damage than other martial arts when properly applied. For people looking for a quick method of self-defense, taiji doesn’t really suffice since, like any martial art, it takes time to develop skill (the idea of “gong fu” is that it is a skill acquired through much time, hard work, and patience) techniques. I’d also add that taijiquan isn’t primarily a form of exercise. The exercise/health benefits found in taijiquan are by-products of a highly sophisticated fighting system.
Taijiquan does not predate Christianity. The Zhang San Feng legend dates back to the 12th century. Chen Wangting’s era dates between 1580-1660. The presence of Christianity in China predates both, since the earliest archeological findings related to Christianity relate to a stele located in Xi’an dated 781.
Taijiquan is based on a philosophy related to the taiji, a state between the wuji and yin/yang. Mantak Chia’s book “The Inner Structure of Tai Chi” talks about taijiquan as it relates to the Universal Force, the Cosmic Force, and the Earth Force and gets very deep into Taoist philosophy even in the first chapter. Chia isn’t “the authority” on taijiquan, but his book does point out basic taiji philosophy. Chen Xiaowang’s book on the Five Levels of Taijiquan talks about achieving, at the highest level of practice, completeness of person. Taiji philosophy does deal with chakras–3 of them in its case, called in Chinese “dantien”. To deny that these things exist within taiji philosophy is to be ignorant of the core principles which undergird taijiquan practice.
Although I can appreciate that other religions may offer gems of truth, as Catholics, we have Sacred Scripture and Sacred Tradition which give us all we need to know for salvation. Being a complete person comes through a relationship with Jesus Christ, particularly through reception of the Sacraments, not through practicing taijiquan. Catholics don’t need to be wasting time with chakra development. If we did, I’m guessing it would be part of the deposit of Faith.
I’ll end this reply with this comment: I searched for many years, asking, studying, and praying about participation. Time and again, I was led out to the conclusion that taiji practice was incompatible with the Catholic Faith. I argued the other side many times, with a lot of the arguments I see here, and in the end, all of those arguments came up short. I wanted to hang on to it and became upset many times when I felt that my practice of it was being challenged in terms of my walk with the Lord Jesus. That alone was problematic and because of my wanting to hang on to practicing taijiquan so badly, I fought for a long time to keep it.