I started skimming through this, wondering where I'd heard these ideas before: then it hit me. Two weeks ago, driving to the airport at 3 AM to catch a 6 AM flight, listening to Kaku being interviewed on this very topic by... Art Bell. Bell kept going off about Shadow People or some damned thing, and Kaku seemed to be going along with it.
Kaku has a great sense of humor. He eventually brings Art back to the science he's on the show to promote. Sometimes appearing to agree to the silly stuff prevents being sidetracked.