The limits of using the term Woo, what it is, what it isn't, and why it should be retired...
in a medical context for more accurate terms such as quackery and fraud.
First, Woo is a catch-all term, and basically has two basic definitions, the first is it applies to beliefs in things that have been thoroughly debunked using science, but still have adherents, Lamarckism is a type of woo, so would the Flat Earth Society, etc. The second definition is slightly more abstract, but its asserting beliefs in things, using scientific terminology, without understanding the science behind it, to support superstition or unsupported assertions, the quantum consciousness(collective consciousness), so called scientific support for the afterlife, reincarnation, psychic powers, telepathy, etc. fits this trope to a T.
That is what woo is, now here it what it isn't, everything else that can be falsifiable, in a medical context this includes pretty much everything that can be tested. When something hasn't been tested yet, it is NOT woo, its simply not tested yet, that's it. I was inspired to make this thread because of the Marijuana thread about the little girl with seizures who is treated by an oil from the plant, and it apparently works. That is NOT woo, indeed, do you know the difference between the naturopaths of the past and scientists of today? Their experimentation was limited by their lack of understanding of things such as bacteria, cellular theory, etc.
Using modern instruments, scientists and doctors today can use the compounds in plants such as MJ, reduce the side effects, if any, isolate the chemicals responsible, refine them, help figure out safe dosages, etc. For many medicines, the difference between a chemical that is useful and one that can kill you can be very small, best to make sure its consistent and safe. They can even synthesize other chemicals that have the same useful effects, but with fewer side effects or lower dosages necessary. This is why its important to know how a substance works on the body, its not enough to know that it works, but also how, so we can understand how to have the same effects repeated in other people, can see if it has other useful affects, etc. This is why double blind studies and research is so important.
Now we move to quackery, which I will consider a subset of woo, but refrain from using that term.
First things first, remember what I said above, anything that is falsifiable is NOT woo, that means the physical effects of acupuncture, chiropractic, meditation, yoga, etc. are testable and falsifiable, so testing should be done on them.
The ideas behind most of these, at least the traditional ones, about chi(Qi), "Life force"
vitalism), Chackras, etc. are simply superstition, discredited ideas, and untestable. That doesn't make the practice behind them useless, just that the people who developed these practices didn't understand the human body, so they made shit up, the results were real, the ideas of what people thought was going on was wrong. Its similar to people thinking that lightening came from the Gods, that part isn't true, but lightening itself is real.
So what is quackery? Well, take what I said above with the first definition of woo, apply it to "alternative therapies" and multiply it by a thousand. For example, chiropractic may help you with lower back pain, that part isn't woo, but it will not cure colic for your infant, that part is quackery, and anyone who advocates for it is a quack. Same applies for pretty much all the alternative therapies on this list, particularly their more far out claims of curing cancer. Vaccinations causing autism, since its thoroughly unproven, and even a mechanism for how it could happen isn't even possible, its quackery.
Frauds are people who are quacks who actually don't believe the shit they are peddling.
And now I move to homeopathy, which I failed to mention before, mostly because it kinda belongs in its own category of wrongness. At least the other alternatives, where they are wrong in how they work, at least its "metaphysical" wrongness. Homeopathy is its own category because it makes assumptions about the nature of matter that are not only unproven, but impossible to work. Its a type of magic, in a way, but trying to make it sound real. Not only do homeopathic treatments have to dilute things beyond the molar limit, that is, you have to dilute less than one molecule of a substance in water, which is impossible, the water itself has to be able to retain a memory of that substance(since it can't exist in the water), and this memory is locked by vigorous shaking, of all things. This is homeopathy in a nutshell.
Oh, and did I mention that the term homeopathy isn't protected by any sort of law? That means that, even if something is labeled homeopathic, that doesn't mean it is "just water", though in most cases its true, sometimes, like in the case of Zicam, it had an ingredient, like Zinc, that had the unadvertised side affect of damaging your sense of smell. But hey, its not like this industry needs to be regulated or anything! 
= new reply since forum marked as read
And using the concept of falsifiability (the basic condition for the scientific method) is important. People need to understand this.
One more aspect should be added as well. While the effect of chicken soup on a cold, for instance, is theoretically testable (it has been, and no definitive conclusions have been drawn; it does tend to make people feel better, but we're not entirely sure why at all), one can at least say that eating chicken soup while you are sick is not going to harm you at all—even if it turns out to be just a wife's tale. (As your Jewish mother might say: "It couldn't hurt!"
The same can be said, for the most part, for the items in your list of non-proven-but-not-necessarily-woo things such as yoga, acupuncture, chiropractic medicine, etc. (The one proviso being that you could be harmed if something serious is at stake and you don't seek a proven treatment.)
I sought chiropractic treatment once for an extremely painful injury that turned out to be a cervical sprain (the chiropractor X-rayed my upper spine and showed me how my neck was like a roller-coaster). The treatments did make me feel better, temporarily, but what helped most were his recommendations for constant ice treatments at home and a set of neck exercises I followed religiously for four or five weeks (as well as sleep on a special pillow): these were all things that I could have gotten from a physical therapist, on recommendation from an orthopedist. The chiropractor was cheaper and closer (and didn't try to get me to take pain meds, which I hate.) And it didn't hurt me: I knew this guy would send me to an orthopedic surgeon if he thought it was necessary.
Then there is that fuzzy line: those "treatments" such as the marijuana for epilepsy you mentioned that are conceivably testable, possibly have some measure of validity, but that could do extreme harm, even kill you, if administered in unscientific doses. Most herbal remedies fall under this category to larger or smaller degrees. Some might not hurt you much, some might be damaging over time, some might kill you. So no, don't go giving pot to your kids.
I go the "do no harm" route. Spraying with a saline solution may help prevent a sinus infection when you get a cold (doctors say they don't know why it works, but it seems to help). It may not really do anything in the end, but it's certainly a benign treatment that can't hurt. And there's nothing else you can do about a cold anyway, except ride it out and hope you don't get a secondary infection. You don't ride out cancer, however, with unproven treatments. Science, however deficient it may be in the moment, is the only way to go. You can always pray on the side, for a little extra oomph, even though it may be useless. It couldn't hurt!
This is my first and last word regarding the recent woo controversies.