There obviously are levels to being intimate. You can be more intimate with someone than with someone else. It also varies with time.
A better way to look at those categories is that they are dominant archetypes (like eigenvectors) that are variably fractionally fulfilled by each relationship. The archetypes are "real" in the sense that they accurately describe/compress reality, much like many datasets can be quite accurately compressed down to some major eigenvectors.
The description still does not really fit what I have in mind.
And backstage intimate is horrible term too. My friends are not intimate nor backstage. Intimate is something else entirely, it does not fit the relationship at all. I talk more openly with them, but I am not intimate in emotional sense with them at all.
The backstage part have similar issues. In what sense are they backstage?
A better way to look at those categories is that they are dominant archetypes (like eigenvectors) that are variably fractionally fulfilled by each relationship. The archetypes are "real" in the sense that they accurately describe/compress reality, much like many datasets can be quite accurately compressed down to some major eigenvectors.