I've heard, on rare occasion, a subtle differentiation between be as a state (to passively embody) and be as an action (to actively embody). The latter form often occurs in parallel with do to add emphasis to the active nature of the verb.
What do you do with all your money?
I be rich.
What does the Pope do?
He bes Catholic.
Does he always be idiotic like that?
Yes, he always does (be).
No, he doesn't always (be).
Rhetorical questions demonstrate a similar, possibly related device:
Why don't you be sure first?
- If I take the time to be sure, I'll be too late.
It is not at all related to African-American Vernacular English and its use of be as a tense marker. It's also not necessarily indicative of a habitual action (e.g., (will) be).
Is this standard? Moreover, is it predictable? Could it be a vestige of a distinction that used to be marked in English but has since been largely lost, or is it a wholly new development?