1) First, my point in listing the paper on Qigong is that, it is a practice which has been established after the "Cultural Revolution" and thus is a sanitized version from a whole babel of ancient texts with a severe focus on practical efficacy and knowledge of modern science. Thus its inclusion under TCM which was promoted by the Chinese govt. In this process some of the possible valid allegorical levels and mystical knowledge may have been lost since they were considered "woo-woo" gilded in mere flowery language. But the end result is something which is concrete and valid enough to be accepted as "Alternative Medicine" which is a good thing. So you have a solid baseline if you start your studies here.
2) Now you might be interested in studying the ancient texts(from Daoism, Buddhism and Confucianism) with all their allegories and flowery language to figure out what might have been lost during the standardization process. But this is quite hard without having the baseline knowledge mentioned above. This is where the hucksters and charlatans have a field day. They take some words/verses/ideas from these texts, interpret them in their own way with no proper comprehension, draw absurd parallels with other similar systems/modern science and hey presto; you have a series of books to sell and a cult to build. The waters have now been muddied. So a student first needs to do some proper research for authentic sources. In this day and age that is not too difficult. For example, you have definitive translations done by "Fabizio Pregadio"(https://en.wikipedia.org/wiki/Fabrizio_Pregadio) who is a scholar on "Taoist Alchemy" which is what you seem to be interested in. See his works here: https://www.goldenelixir.com/press/_sub_taoism.html