sorry for the delay in replying. It's a busy time of the year :)
Above you implied that loss of appetite is a sign of illness. I could not disagree more. Some of the best states we ever experience come with complete lack of appetite. In fact, health can be measured in how long a person can go without food while feeling great and having plenty of energy, both mental and physical.
Above you also brought up the point about the difference between fasting and starvation. It is clear that starvation starts as a fast and then --when?-- spills into a "pathological, destructive process".
Regarding this, a few years ago, I read a few mice studies about the changes their GI tract undergoes during various stages of fast/starvation. At first, the small intestine atrophies -- until the animal runs out of its reserves. Guess what happens then? According to the research, when an animal reaches this stage, it greatly increases its activity, in other words, it appears to get a sudden spur of energy. It turned out that at the same time the small intestine is restored to normal functioning state. This is Nature's 'last call' -- if the animal does not eat soon, the catabolism of the vital organs gets out of control and it becomes very difficult to stop the downward spiral to death.
So, according to this research, it appears that Shelton brought his long term fasters to the brink of irreversible starvation. That's what he called "fasting to completion" and listed its signs -- so similar to mice at the 'last call' stage. I believe it was irresponsible of him to advocate that people fast until reaching this stage. It is far too risky, especially since how long it takes for a person to reach this 'last call' stage is very individual and depends on many factors (of which fat reserves is only a small part) and the window within they must eat is narrow.
You also said that "if we are well and have health in abundance" the body will "keep-up with its normal processes of nutrition and drainage, making the fast superfluous". -??
It is as if you chose to ignore the point I made above that frequent fasting is the way of life. We evolved with frequent fasts, both short and long, and Nature learned to rely on them to do her housekeeping, a far more thorough kind than the daily maintenance that goes on otherwise.
Fasting is never superfluous. It is the way of life and the most natural thing to do. Because our food is abundant now and its supply is reliable, we must fast voluntarily -- simply because our physiology evolved to rely on it for its optimal functioning.