Re: Shioda, Tohei, and Ki Things
A few points.
Minoru Kanetsuka was not directly related to the Shiseikan. His relationship came indirectly through Takushoku University, also attended by Tanaka Shigeho (and, incidentally by Masatake Fujita).
After William Smith separated from M Kanetsuka in the early 80s, Terry Ezra stayed with him in the BAF. However, Terry had other influences, notably K. Chiba and healer John Kane, and I think they grew apart from quite early on.
I trained with Kanetsuka Shihan almost every day for about 5 years, between my return from the US and my departure for Japan. From what I know of Yoshinkan training, this was very similar, but he also began to study M Saito's aiki-ken and aiki-jo and also the Kashima swordwork practised by Chiba's father-in-law, M Sekiya, who stayed in the UK for a year. He was nothing if not eclectic.
Rather than S Yamaguchi (aiki, in my opinion), I think the Aikikai shihan who embodies kokyuu most clearly is Hiroshi Tada. I trained/train regularly with both shihans here in Japan and they are quite different. Both awesome, but quite different. The one common link is that both do (did, in the case of Yamaguchi Sensei) aikido and studied (stole) directly from M Ueshiba.