I think you have too much credence about the supposed "uuu" hits. Do we have a transcript for any of the readings in which they supposedly occurred? If not, My guess is that they're the result of the psychic arriving, with the mark's help, at something specific over a period of questioning, but the person who related them forgot about the questioning and just remembered "he knew about the nickname."
It would be impossible to come up with reasonable alternate explainations for all of them, but the Miss Piggy one, when I heard that a plausibe alternate explanation occurred to me immediately:
What if what happened was more like this: J E is talking to a woman with a Hispanic accent. He throws out something like "she had a nickname based on her weight" (it could have been as vague as "she used to be called something because of her weight" which would have included insults, too, actually... But let's go with what I've got.)
The woman gasps, and says, "Yes, we used to call her Miss Piggy!"
Sounds awesome, until you know that Gordita is a super common nickname for chubby little girls in Mexico, and possibly other Latin American cultures as well.
And that's not even using the even more vague remark, which could mean insults, or could refer to underweight instead of overweight.
It's impossible to do this for every example, of course, but I don't see why you'd give those examples any weight at all without a recorded instance of such a "uuu." Even then there are other possible explanations, like hot reading, but at least if it were recorded we would know it wasn't as simple as "altered by memory to be more awesome than it actually was."