I've seen 達人and 名人used to indicate master or expert. What's the difference? I'm not familiar with either word, but just looking at the characters, would seem to indicate 'accomplished' (ie an accomplished pianist). While seems more like 'renowned'. Is that a valid assessment?

Consider the following:

> as a kanji has the meaning "accomplish", "(to) reach"
>
> as a kanji has the meaning "name" or "reputation"

Kanji compounds:

> : "achievement"
>
> : "famous, celebrated"
>
> : "fame, prestige"

And in Chinese, `(míng rén)` has no connotations of skill as far as I know, it simply means "famous person". `(dá rén)` however means "expert" and does not imply fame.

I would say your assessment is a reasonable one.