Yoshihiro or Yoshiyuki would likely be called Yoshi by their friends.
I completely support the defensive adoption of a sardonic butler-persona for everybody on the other side of a cash-register. :p
"Why should I have to change? He's the one who sucks!"
I do think Dale Carnegie overemphasizes the importance of saying people's names, and in fact saying people's names in conversation often sounds forced and manipulative, but maybe that's just a cultural shift over the past century.
But, yeah, it usually sets off my spidey sense when somebody keeps using my first name in conversation. It's just seems weirdly unnecessary, so it makes me wonder why they're doing it.
Doc Rivers is an awesome name though.