I currently own this book and I agree, it is very interesting indeed. The author really goes indepth and provides some interesting explanations. However, most of what he says is mere conjecture. His theory is a very interesting one, and a lot of fun to read, too. However, I seriously doubt the validity of the claim that shotokan karate was being used to defend the king of okinawa. Linear karate, as we practice it today, did not exist in okinawa - it didn't come into being until funakoshi modified his karate and introduced it to the japanese. Okinawan karate used renzokoken - continuous fist fighting, not ikken hisatsu - one strike, one kill. Okinawan karate was closer to its chaun fa roots, and retains the closeness to this very day, just go train with an isshinryu or uechiryu karateka. As a matter of fact, ikken hisatsu is a concept from japanese swordsmanship, not okinawan karate. Funakoshi made ikken hisatsu a part of his karate so that the japanese would embrace it, sort of how he changed the names of the kata from chinese to japanese. So a lot of his claims, while interesting, are not exactly valid. He presents the information in a "ok, this is what could've happened" type of way, then he treats it as though it actually did happen. It is a very interesting read, though. It is one of the few books that I have read all of the way through. I really love his take on bunkai, and he has some clever uses for them. I agree with his opinion on building character, too. Karate doesn't build good character, it teaches you to act japanese, they are one in the same in japan. I thought that was classic, and I believe that it is true. All in all, a very entertaining book, but it stretches the truth somewhat.
Train hard and the answers will reveal themselves in a way that you can truly understand.