There is no new information in this book that cannot be found in other, more credible, sources. Please stalk my profile and look at my "Psychic" shelf of books, for a start. I have been studying the tactics of "performance mediums" for quite a while now, seeing as I have a keen interest in mediumship and the afterlife.
Here are some things to look and listen for with a "performance medium" that are red flags:
"Father figure" / "Mother figure." Depending on your age, I bet you can think of any number of people of either sex that are older than you. If I asked you to think of an "uncle" / "cousin" / "friend of an uncle," etc, I bet you can think of someone. Why would this random dead person want to talk to you? Wouldn't it make more sense for the person you have been thinking of in the days leading up to the reading to be the one who shows up for you? It's not like dead people have a full schedule and they just can't fit you in today. In fact, they can be in multiple places at once. Don't you think they would be right at the front of the line ready to make contact?
Spirits who mumble, as in "I'm hearing a 'G' or 'J' name," and all the variants where proper names are unclear to decipher. Clairaudience can often be mistaken as your own thoughts, because it's the same part of the brain that deciphers language that's being used. People don't mumble in their thoughts. Clairaudient voices sound like whispers, and while the volume might vary, it's not hard to make out sounds. They are clear statements to be heard, or else you wouldn't be getting any information.
Spirits who seem to be fixated on irrelevant details that could apply to almost anyone. "They're pointing to a fence, is there a fence around the cemetery they are buried in?" You've got this once in a lifetime chance to talk to loved ones who are alive and you're fixated on a FENCE? I'd like to point out that in true mediumship, there can be evidence given that might seem mundane, like "there's a box with a watch," but the kicker is that you were demonstrably alone with the watch. And if they go on to say "and the last time you opened it the clasp caught in your hair and you thought of how your cat would do that to your hair," well, that's pretty damn specific.
A bunch of questions. Mediums don't need to ask questions from the sitter. They might get visual pictures, sensory impressions, or hear things, but it is their job to pass along their impressions and have the sitter determine if it is useful. Go through a transcript from a performance medium and notice which statements came from the medium and which were answers to a question. There might be a few hits, but consider how likely those guesses would apply to most people.
Picking a number and then fishing around for its significance, ie: "three days, three months, three siblings, three years." Fake Tarot readers love this tactic, too. However, if one of those "three" groupings made sense to you, all of those things are COMPLETELY DIFFERENT topics. What are they talking about? People? Time? Dates? How is any of that helpful or useful? The equivalent in fake Tarot readers is they pick a card with a number on it and proclaim divination by seeing an event happen in "three days, three months, or three years." None of those dates are helpful.
John Edwards' personal differentiation tactic (apart from the speedy nature of his patter) is that he says "no" to people when they reject his guesses. As in "there's a father figure who was interested in cars..." and the sitter says "no." In order to make it look like he is correct in getting his answers from spirit, he will say "no" and then wait for the sitter to think of someone else--anyone else--that he can then claim a "yes" to. Should that fail, he will either rephrase the statement, move to a different topic, or tell them to "take it home" where it will "make sense later" (another cold reading tactic where the answer cannot be verified in the moment).
There is a concept in forensic statement called the embedded confession. In it, the person making a statement inadvertently "leaks"a true statement, such as "It gets even more ludicrous that we’ve obviously hidden her somewhere incredibly well where nobody’s found her." In this book as well as Infinite Quest, Edwards spends an awfully long time on admonishing people to not fake their abilities, and to have hubris, which is a quality specifically lacking in many of his own stories, almost as if it were an embedded confession.