It is not exclusive to Okinawan Karate. For example the branch of Shindo Yoshin Ryu as practiced and handed down from Takamura Yukio is referred to as Takamura-ha Shindo Yosihn-ryu, but I understand what you mean.
It does seem odd to suffix Ohtsuka with "ha" as that doesn't make sen...
Hello, I think the grading to 5th dan depends on the group. In my group it is honourary, however I know that you can grade with the JKF Wadokai in Japan all the way up to 8th dan (not many people have passed this exam though).
Wado kai (as in JKF Wado kai) is a group not a style. The karate they practice is Wado ryu. Originally all Wado practitioners were members of this group and today it boast some of the finest Wado-ka amoungst it ranks including Arakawa Turu, Takagi and Ohgami to name but a few.
@ryukuykenpo74
If "there" is where you are, I don't think I want to go lol.
Gary