"The question was concerning the partners head and shoulders moving back before his center."
Interesting then that you choose to speak of the feet and not the hips.
"Just think about this if you are able. There are people out there who may be reading your comments. You are trying to tell them that a book that as stood the test of time is wrong."
No, I am telling them that the book is right, but that it only describes one of hte situations we face in dancing - the one that is simplest, but least common, which is the case of no rise and no fall, which means no change in speed during the step.
Steps with rise or fall simply require different technique than that of a plain level constant speed walk.
"Page 13."
Page 13 describes a walk with neither rise nor fall. It is not direclty applicable to cases with rise or fall, which are similar but not identical in all respects. One of the key differences is when the heel lowers.
"You wrote that the above description is of a flat walk. Which must means that you beleive there is a rise on some Backward Walks."
You bet - the ones that say "commence to rise" or "rise"

"As most of us are aware there is body rise only. Quote page 171. If foot rise is used, the flow of the figure will be seriously restricted."
Depends on which part you are dancing - if leader you use foot rise more often than as follower. But this is beside the point, because the earlier heel lowering is required in the body rise case, as it is in the body fall case.
"Trapping the moving leg. Do you really believe that both knees are bent."
Yes. It is very rare for the knees to be bent different amounts, except in picture lines (this is a fairly basic rule of dance technique). On lowering, when your standing leg bends your moving leg will soon start to bend as well. By the time you moving leg finally starts closing, both legs are quite bent.
"What would that look like."
The kind of dancing that wins Blackpool...
"How are you going to start the backward movement of the moving leg with the heel in contact with the floor if the leg is bent. Quote page 13. The foot is drawn back with the heel on the floor."
I'm talking about a case of fall, in which case it is the toe not the heel of the moving leg that is contact with the floor. You seem to still be confusing the level case (what the book discusses) with the fall case, where I said the books details are not entirely applicable.
"At the extent of the stride both legs are straight, the knees are not rigid."
True in some cases for some dancers - but beside the point because we are not talking about the extent of stride, but what happens as the body starts to move over the just placed foot.
"Please feel free to provide name of Technique book and page if it differs to any of this."
Same book you are using, but reading it a bit more carefully than you are.
"Example Waltz Natural Turn Commence to rise at the end of one. That means what it says. Not at the beginning of, or half way through, it means after step one is completed."
No, it means you commence (begin) before the end of step 1, not after (at the absolute latest, at the instant of foot passing)