(1) does it cause deterioration of the joints?

I doubt it. Not unless you inject it directly into your joints.

(2) why is white vinegar frowned upon by many and applpe cider vinegar touted by others?

People belive all kinds of strange things about "natural" remedies.

(3) Does it contain fructose?

The sugar is converted into acetic acid to make it into vinegar, so no. Any fructose left will be in trace amounts. Traditional balsamic vinegar is an execption as it still contains sugar, cheap versions have sugar added to it.

(4) Is it insulinergic?

No.

(5) How much can one consume for detox/blood alkalizing purposes?

Vinegar won't detox you or alkalize your blood.

(6) Does it increase energy?

I doubt it.

I know that even on paleo/no soap/no shampoo I still had some pretty rough dandruff/dry scalp issues.

Washing my hair and beard with apple cider vinegar killed the dandruff, literally in one washing... plus it makes your hair look great.

Vinegar does not cause deterioration of the joints.

I didn't find info on all of your questions, but you can look around these sites.

These links will help:

http://bodyecology.com/articles/apple_cider_vinegar.php

http://www.apple-cider-vinegar-benefits.com/index.html

I was not able to find a clear discussion of why steer away from white vinegar and toward raw apple cider vinegar...but in a lot of the information, white vinegar is used a cleanser and as a cheap form of vinegar. ...raw apple cider vinegar is probioitc...so it does more than just 'cleaning' it also rejuvinates.

...if you are taking this for acid reflux on a regular basis...then this tells you something else is the issue and should be dealt with more directly versus symptoms...also with using it for dandruff, ect (which I have). that is, this can be used to address symptoms and deal with issues on a certain level, and so valuable to keep around. but if this is being used on a regular basis...then a better look under the 'hood' may be in order and address the issues at a more systemic level.

also, in general, having some rotating fermented foods seems to be an adaptive approach (and in some ways a paleo perspective)...just rotate them. ...sauerkraut has cabbage and can be estrogenic, miso - the same, etc. ...but also good to rotate because there are different biotic strands...and roughly 80% of immune system is in gut (also where most of seretonin is made...but us moderns tend to have too much seretonin or are resistent...read Lights Out)...and there is more neurons in our gut than head...so 'the first or second brain' thing.

hope this helps