*Stop* calling wool a "living fiber". The fiber is actually dead when it leaves the follicle on the sheep. That's why you can cut it off without injuring the sheep. In that respect it's just like hair. The only part of the hair fiber that is alive is the follicle.
Yes, wool is sensitive to extremes in pH, but so are most things. Soap, however, is not evil. Soap is not unbalanced in terms of pH. When soap is made, sodium hydroxide (a strong alkali) is mixed with fats to create the soap. The amounts of alkali and fats are balanced so that all the alkali is consumed. In fact, many soaps have excess fats in them to provide for a more emollient feel. These fats can be left on the skin or whatever is being washed, but are usually rinsed away. In any event, using a soap does NOT automatically result in pH imbalance in whatever is being washed. If a soap was a harsh alkali, it would burn your skin. Not just dry it out, but actually produce a chemical burn. I've used Ivory soap for years (it is 99.99% soap) and haven't had a burn yet.
The choice between soap and detergent depends to some extent on your water supply. Hard water and soap do not work well together. That combination produces soap scum, not only on your bathtub but also on your clothes and the fiber you are trying to clean. In that situation, you can either use a softening agent in the wash water or use a detergent. Detergents were developed to work with hard water situations and do a much better cleaning job than soaps in that situation.
Yes, washing wool to remove the lanolin, dirt and other contaminants can result in the fiber feeling dry. It feels dry because the lanolin and other natural oils have been removed. Your hair does the same thing. You have two options: either don't remove all the lanolin/oils or to replace them with some sort of emollient or oil. In any event, the fault does not lie with the cleaning agent, but with the application of that cleaning agent to the fiber.
On protecting the environment:
Occasionally the bashing of acrylic fibers is done under the guise of protecting the environment. Acrylic is bad because it is not "natural" and is made from petroleum products. These folks advocate cotton or wool because they are better for the environment. Have you ever looked at what goes into cotton production and its impact on the environment? Do you realize that cotton is one of the most chemically treated crops on the planet? Cotton production uses 11% of the pesticides and 25% of the insecticides produced in a year despite being only 2.4% of all the crops grown in the world (Source). The plants are sprayed repeatedly to kill weeds and insects. Prior to harvest, defoliants are used to destroy all the leaves so the cotton won't be contaminated by leaf matter. Some defoliants are organophosphates and have neurological effects on birds, mammals, fish and invertebrates. (As an aside, organophosphates are also used in nerve agents.) Non-organophosphate defoliants are still highly toxic in the environment even if they don't have demonstrative reproductive or neurologic effects in humans. Field runoff still kills fish, plants and aquatic invertebrates.
So perhaps cotton isn't as environmentally friendly as you might think.