The number of stars indicates quality. When people see a book title suggesting (like in "Flim-Flam! Psychics, ESP, Unicorns, and Other Delusions") that ESP is a mere "delusion", it is possible that they are not willing to give very high ratings to that book. I have already mentioned on this forum that
apparently 41% of Americans believe in ESP:
http://www.livescience.com/16748-americans-beliefs-paranormal-infographic.html (I suspect the number of Americans who
really believe in ESP is actually much higher, and close to 100%, but they are not necessarily ready to admit it in a poll).
"Quality" is a perception, Michel, not a number. It's also entirely possible that the only reason Renier's book got a (slightly) higher rating than Randi's is because most of the people who are going to buy and read, then review, the book are the ones already disposed to believe in the nonsense in it; so a higher "quality" rating is just an effect of confirmation bias.
I'm also not sure I understand why you would "suspect" that people would lie in a poll, making
it unreliable when its numbers aren't high enough to suit you, but a bookseller's rating system- effectively a slanted poll- would have results that
are reliable in confirming the claims of the book being rated.
Now, regarding Renier's claims, even if some moderate and polite skepticism is appropriate (and perhaps sometimes even more than that, see Daylightstar's post above), I think they are not necessarily as absurd and illogical as they may seem at first sight. Take for example her "prediction" of the assassination attempt on Ronald Reagan. This idea was probably present in John Hinckley, Jr.'s mind a few hours before he shot at Reagan, and even also perhaps a few months before. Then, Ms. Renier, who is perhaps a sensitive lady with an interest in criminal affairs, could have correctly perceived this idea through ESP or telepathy, way before the crime took place. There is nothing irrational and unscientific here.
The only thing I can find as to her actual "prediction" of the assassination attempt on Reagan is
here:
Right now I feel very insecure about saying this, but I keep feeling problems in [Reagan's] chest. It's not a natural problem, perhaps it might come from outside. . . . I see an illness coming around him. Part of me is blocking it because I don't want to see the answer...I feel like it would happen within a four month period."
Yeah,
that's rock solid- he could have had a heart attack, and that "perhaps" is just enough waffle that it would have qualified as a hit. Even something like "I feel Reagan will be shot in the chest" is not all that impressive, since there's a history in America of Presidents being shot, two of them in that general area, one in the back (not to mention the misses, like twice relatively recently with Ford).
She also, apparently, did some sort of presentation at the FBI training facility in Quantico, VA, where, according to an agent there (Robert Ressler, apparently a supporter of her), the "prediction" went something like this:
...she said she felt that [Reagan] was having a heart attack in the future...some sort of chest pains . . . and then she clarified it by saying no, it's a sharper pain and it is a gunshot....I believe she said in the left chest because she was patting her left side, and that he would not die...
...she went on to say that . . . later in the fall, October, November, he would be killed in a machine gun assault on a parade stand by many in foreign uniforms...
Question: Do you recall if she specifically said the second shooting would be President Reagan?
Ressler: She thought it was President Reagan.
Question: She was wrong on which President it was, then?
Ressler: Yeah...circumstances were uncanny in their accuracy [but] it turned out that it was not Reagan, it was Sadat."
Two different claims being conflated here, Michel- and the conflation makes a "hit" for one serve as proof for the accuracy of the other.