3. I'm training in kickboxing and the adult classes seem obsessed with leg stretching and cardio workouts. In conversations I've tried to discuss the importance of the alignment of the spine as a central issue, but no one seems to care. Am I alone on this?

... No, you are not alone and soon or later your fellow kickboxers will join you. Every aspect of the fitness workout is important and they complement each other, but when we neglect the care of the spine it can lead to serious troubles.
... As soon as someone begins to discuss backs, posture, or breathing, we all tend to sit up straighter, pull our shoulders back, and squirm in our chairs. You may well have done so when you began to read this. Although this is a good reaction generally, it does indicate that we probably were not sitting or standing properly in the first place. Inactivity, together with poor body positioning does more damage to backs and necks as we age than any vigorous activity such as heavy lifting, tennis serves, or even minor traffic accidents ever could. Although these latter are responsible for many injuries, it is notable that most of the movements that "put the back out" tend to be simple ones like bending too quickly to pick up a sock, reaching over the bed to tuck in a sheet, or lifting a suitcase out of the trunk of your car. What we often fail to realize at these moments is that the fault lies not in the actions themselves, but the neglect to which we have subjected the spinal system for years, and in some cases, whole lifetimes.
... Although there are those who have been born with curvatures or anomalies, and others whose injuries have produced conditions that require special care, most of us have allowed our spines to get out of line gradually. Over time, surrounding tissues and muscles have adapted and compensated. Even when told to sit up straight we may feel in line but in fact there may be subtle bends in the spine. This can cause an unnatural movement of components such as what occurs when your car wheels are out of alignment and the tires wear unevenly. As well, when we age, the spine’s natural shock absorbers begin to lose their elasticity, and a severe jolt, especially when vertebrae are twisted out of line, can cause them to fail or break down.
... Fortunately, in recent years we have come to recognize, with the help of sports physicians and movement therapists, that these defects can be avoided, and in many cases reversed, by exercise, good posture, and more respect for the framework that supports the body.
... The martial artist is already toiling in this field, working away on spinal alignment whether or not he or she has ever experienced back or neck pain before. In much the same way that the students of martial art are trained in the art of breathing, they learn the art of standing and sitting correctly from the very beginning of their practice. In order to move well, the martial artist requires a body that is well tuned and in good running order, one in which reflexes, balance, strength, flexibility, and intrinsic energy are responding in harmony. This is not possible without good alignment of the spine, head, and body.
... Since so much martial art training is based on the disciplined and supervised execution of good technique, it offers an excellent opportunity for the development or repair of alignment. Learning the location of your center of gravity and how to lever or rotate the body around it, is practiced from the first day, and continues to a refined subtlety at advanced levels of training. From a health and fitness point of view, elegant technique and feats of balance and agility are all in aid of a relaxed, natural stance.
... Developing self-awareness, or a kinesthetic sense of where your various body parts are and how they are moving in the execution of technique, is valuable both in and outside the dojo. A martial artist requires the ability to move quickly and change direction, but also to hold his ground in a stable stance when necessary. Although these demands may seem to be contradictory, they are in fact the principles of yin and yang at work; both are needed for balanced performance.