thanks for the details, sorry.. so many questions, just hope you are enjoying writing your book and wish someday i can read it

i've just seen this about acv, which caught my attention

http://www.physicsforums.com/showthread.php?t=228277

"By taking a little apple cider vinegar before a meal, you can increase stomach acidity and thereby improve digestion and nutrient uptake. "

But since vinegar is less acidic than stomach acid wouldn't it follow that vinegar would reduce stomach pH? (unless the watery contents of vinegar flux out of the stomach at a higher rate than the acidic contents of vinegar?)

I think you are correct. For older people, stomach acidity (pH) may go up, so maybe in that case vinegar would lower pH. For people with normal pH I don't see how it could lower pH overall. My only guess would be that adding acid lowers the pH of chyme (food) before the stomach acid has started to be produced.

Also other says

If you have low acid in your stomach you will have poor digestion which most people think is that they have too much but in most cases you don't have enough. If you injest ACV and you feel better then the problem is your stomach acid is low but if you feel whose and feel that you acid burning sensation then ACV is going to nothing for you. So if you stomach acid is low then ACV will increase the acidity in your stomach for a positive reaction but if you have a normal or high amount of acid then you will get a negative reaction.

Is it correct or just theories?

but also i think they aren't thinking in the nutritional value of the acv, which gives to the body the vitamins for proper stomach acid