Humans. Human beings. Semantically, is there importance in the differences between them, or are they interchangeable? ~

...."are there importance in the differences" .... (sound right to you?)

Interchangeable, but with some sort of verb or something before human.

Humans - is a generic classification, including all of us.
Human being - refer to an individual human, yourself or someone else. The word imply that every human is different (in his way) from every other human. that is often good to remember
So while the 2 words can be used interchangeably, they rarely are.

everyone is different