Re: How to address a Shihan, Sempai, or Sensei?
From a Japanese language POV,
As mentioned, Shihan is a title, not a term of address. Shihan are called "Sensei" or "Name-sensei".
In a school context and in some work contexts, "sempai" can be a term of address, either by itself or as "name-sempai". However, this is generally not done by adults in the dojo. Sempai is never a title, it's more like a state of being.
Incidentally, Sean Connery in Rising Sun notwithstanding, "kohai" is never used as a term of address.