Did I say I reached the mountain top, no, I don't think so. I have met a couple and know of a few more who I will never be on par with. Believe me I am not there, nor may I ever get there, it is about the journey, not the goal. However, my road is a lonely one. But that is my journey.
As far as the current head of Matsubayashi, I have heard similar things. If you had heard what I have heard as well, I am surprised you believe he is the most knowledgable. In 1960 other than Nagamine, Jokei Kushi (Okinawan Sumo Expert, who of course knew nothing of ground fighting
), Seigi Nakamura, and Shinyei Kyan where the most knowledgable. And as far as Nagamine's teachers go Kyan, Arakaki, and Motobu were probably as self destructive and maladjusted as anyone. Kyan loved whores and gambling and taught the same to Arakaki. Motobu of course loved to start fights and assault people. However, Nagamine sought to emulate their karate, not their character. In fact, I could see Nagamine going out of his way to ensure his students were of the highest character so they would not fall into the same trappings of his teachers. I have also heard that Arakaki did not die due to stomach ulcers from worry, but from a gamble gone wrong involving a fight. You don't think that Nagamine would come down hard on anyone exhibiting similar behavior do you and possibly NOT share everything with such an individual? In addition to him I am suggesting Nagamine kept a lot secret from a lot of people.
As far as Ueshiro, he learned much more than to hit a makiwara with no fingers. Try becoming an expert in bojutsu, as well as one of the best street fighters in okinawa with no fingers. Oh, believe me, there are and were far greater men and karateka than me.