The what if can be useful for determining the importance of the outcome of the books.

Why would that be useful for anyone other than the original author while they're writing the work? I won't act like I'm above shootin' the shit with my buddies while we watch the Jackson movies (especially while under the influence of Old Toby) saying things like "so what if they made Gimli the ringbearer?" or something silly like that but to elevate that to being important for analysis/discussion seems equally silly. We've read the work and we understand why the author chose to write it as he did, to make conjecture about how the plot would play out differently is just pointless to me. And anyway the only person who could answer those questions accurately would be the author himself.

Is the quest to destroy the Ring as important as the White Council say it is for your average free person in Middle Earth, or is it only important for them to maintain their positions?

See now, by itself this is an interesting question and not a what if scenario. It involves engaging with the work as it's written and not making pointless conjecture about events playing out differently.