I think you have to assume going in that it's all lies, and go from there.  Without that assumption, paradoxically, you have nothing to hang your hat on.  Which leads to the kinda confused and rambling nature of your questions, which nevertheless, I will try to address.

Any woman's reviews that I am looking at, I really have no way to figure if any of it is BS.  Like another poster said, I look for newbie reviewers and discount those.  I also look for reviewer handle that I might recognize.  I look for other patterns, like multiple good reviews just prior to a visit, etc. If I did suspect  that all her reviews are a BS campaign, I would pass on her, since there are many women out there, and I want to reduce the risk of disappointment.  Already take many risks, no need to take more if you can help it.

If I did see a woman that I was disappointed in, most often I would not review, since I don't want negative reviews associated with my handle.  Generally, if I can't say anything nice, I won't say anything at all. If I can say some nice things blended with a couple of "suggested improvements", I may go ahead and review.  Given that, I've learned to also read between the lines.  For example, if a young hottie came to visit, and few if any reviews are posted on my local board soon after, I can guess why, and it is probably not guys trying to keep her to themselves.

Saw a very pretty upmarket hot young blonde, she was 1/2 hour late, left door was open when I finally get the room #, she was in bathroom, another 20 min. before she emerged.  Pleasant, but hyped up, (not her 1st time w. me) generally unprepared and my personal pet peeve, smegma!  No review from me, and not surprisingly no reviews from anybody else during her visit.