Re: non-Japanese cannot become shihan anymore?
I've been following the topic with some interest and, dare I say amusement.
It all hinges on how important you consider the title of Shihan.
As Ruth said earlier in the UKA we just consider it as a teaching title, which for sure invests the holder with some responsibilities but in itself does not confer rank.
If you like our Shihan is the "first amongst equals" in that virtually all decisions are made collectively by the Shidoin;gradings and teaching is shared out as equally as possible.
As far as Hombu Shihan being somewhat different - well of course. They are in direct contact with more advanced practice than most of us could dream of as well as being charged with transmitting the latest Aikido developments.
Seems to work for us.