I'll try to elaborate where I can, but I've been intentionally vague for a few good reasons and this is definitely going to be a longer post. As you've probably noticed, Crowleys comment in Liber Al states that the reader should burn their copy of the book after reading it, and that people who talk about its contents should be shunned as "Centres of Pestilence". This is frankly the most wise piece of advice in the book in my opinion as it's an inherently dangerous book. Not bad, just potentially dangerous in the same way that holding a loaded gun is. The reason for this is that Liber Al is inherently Qabalistic and can help you access some deeply shamanic spiritual experiences if you follow certain instructions throughout the text, but it really makes you pay for it. It gave me one of the most profound shamanic and even psychedelic experiences of my life (great!) but resulted in me being forced to spend a month in a horrible mental hospital (not great). Fun stuff, but it can be like the metaphysical equivalent of shoving a fork into an electrical outlet if you're not properly grounded. I certainly wasn't, but your mileage may vary. It's also important to note that Liber Al is fundamentally Qabalistic and requires Gematria to understand, so to understand the book you need to learn Crowleys Qabalah which is problematic for reasons I'll get into earlier. As for Yoga, it's very much the same thing. Despite his mysticism, Crowley had a very materialistic approach to his practice of "do whatever works the best and fastest". One particular example of this is his instruction to hold a yoga pose so long that it begins to hurt, and that pain is a sign of getting better at it. This is, in reality, HORRIBLE advice and will just result in self inflicted injury. I actually tried this myself and all I had to show for it was a few Physiotherapy sessions to fix my knees! By and large, Crowley played too fast and loose in the name of progress. His Qabalism is another tricky one, but for reasons that are a bit too lengthy (and very subjective) to get into entirely but I'll try. The original Kabbalistic tree of life is indeed Judaic in origin, only dating back from the Medieval period and it's a wonderful filing cabinet that can fit everything in the universe within the container of "God". Everyone else loved this idea so much that they used it with their modifications, including Neo-platonisn and astrology. Enter the 20th century occultists who use it with their own pagan revivalist gods and at this point you have a system that is quite different from the Judaic Qabalism. As for Crowleys Qabalah being problematic, this is unfortunately experiental as well so I'll say learn and do what you will and maybe you'll have better luck than me. In my experience though, higher level Qabalism requires a level of piety and submission that I believe most people are incapable of, specifically when crossing the abyss from Chesed to Binah, and then dealing with Binah itself. Binah is pure Saturn in its most severe aspect, and it is a harrowing ride. This isn't me pontificating from an ivory tower; I was incapable of that piety, and my experience of the Tree of Life resulted in me being almost violently killed. A specific example of my troubles with Qabalah is this; a common Qabalistic dogma is to experience every phenomena as a direct revelation from God. This may sound nice and pleasant, because hey God is talking to me, but no. Having experienced it, New Aeon initiation in this way is TERRIFYING. We live in a scary cruel world, and believing that every awful piece of news, every snide sarcastic joke on tv, every laugh, every insult is a direct communication from God just for you is not enlightenment. It's PSYCHOSIS. There's a reason Crowley became so mentally ill later in his life. Do what thou wilt, but my advice? The Rabbis say that you need to be at least 40 years old and married before learning the Qabalah and even then it's a closed system for those who weren't born into Judaism, and I think that's very fair. You need that sort of unshakeable lifelong faith in that Capital G God to get you through the really tough parts. Furthermore, if you still want to learn the Kabbalah go to the source and learn the real proper Judaic Kabbalah found in the Sepher Yetzirah. It makes much more sense, the pathways between the sephirah are linked much more sensibly (the paths on the Hermetic tree follow the major Arcana of the Tarot which in practice makes no sense Kabbalistically), and the piety it demands of you is much more sensible in the context of a proper Abrahamic religion. Having a general working knowledge of the Kabbalah is definitely a good idea, it's always nice to learn, just be careful and don't fuck around with it. Sorry to turn this into a self righteous rant. Like I said, I got burned REALLY bad by Crowleys very flawed methods and I would hate if someone had the Qabalah inflicted on them in the same way Crowley inflicted it on me through his misguided methods. Learn if you must, just very be careful. Anyway, I hope this long rambly message helped explain things to a degree.