The paper reads:
Another rarely invoked constraint is that it be superior to books and printing in at least some ways without being markedly inferior in others. (The previous remark seems to disallow known commercial display devices from consideration.) "Personal" also means owned by its user (needs to cost no more than a TV) and portable (which to me means that the user can easily carry the device and other things at the same time). Need we add that it be usable in the woods?
In this context, it be would be considered a shortened form of it needs to be. The author must have thought that the "needs to" didn't need to be said, because that meaning could be inferred from the context – namely, system requirements.
When reading the entire paragraph, this language sounds natural to me, not "upper class" nor archaic. If the first sentence didn't begin with:
Another rarely invoked constraint is that it be superior...
then I imagine the sentence could have been changed to read something like:
It must be superior to books and printing...
but the word "constraint" eliminates the need to use the word "must" like that.
The last sentence might read awkward on its own, but it doesn't read awkward at the end of that paragraph.
As for your last question:
Is there only one meaning to "it be"?
I would guess not; instead, I think it would be context-dependent.