:-/
Is this a piano method or what?
If so, where does the piano come in?
The Alexander Technique, just like most of the other techniques mentioned, are not specific to piano playing. They cannot, and there is no "technique" specific to piano playing. In order to play the piano well, one must learn to sit correctly, in order to sit correctly, one must learn to stand correctly. In order to sit down, one must learn how to bend. To get to the piano, one must learn how to walk. Etc., etc. you get the idea. All those techniques teach how to use the human body in the way it is meant to be from an anatomical/physiological point of view for all aspects of life. Piano playing must not be isolated from the rest of life, or bad things are bound to happen!
The different techniques may differ to some extent in their premises and goals, but they seem to be anatomically sensible. They are neither mystic nor have they anything to do with hippies, though some schools may go as far as applying their techniques as alternative healing methods for certain ailments.
Not quite sure what is going on really...
That should not be! You must understand the basic ideas before you start out, so that you know what to look for. It should have been pointed out to you that it's all about the major points of balance in the body and to learn how to keep them aligned and balanced. I think one of the biggest differences to classical posture myths is that, in classical posture, muscle action is used to bring the body into certain postures and to keep it there. Alexander claims that the skeleton inherently knows what the correct posture is. Muscle action only leads to abnormal ("bad") postures. An emphasis is therefore to learn how to release all muscle tension, particularly in the neck.
I also sense that you may be unsure about why you are doing this. It helps if you convince yourself that there is a lot wrong with your body (I only assume this, of course), that it can be fixed, and that the Alexander Technique can help you. And of course, it can help you prevent things in the future.
If you are still unsure, check out:
https://www.alexandertechnique.comMartha would say "It's a good thing", and I would agree.