Do you mean the three sample questions I gave as things that can come up during mapmaking, Rosemary, or are you confusing me with dwndrgn and her three numbered points?
I certainly do believe that fantasy writers can benefit from asking these and questions like them very early in the writing/worldbuilding process. It doesn't have to be the first thing. Mapmaking is one way to stimulate those questions, and for most of us a comparatively easy and fun way to do it. (If you don't let yourself get too distracted designing compass roses and sea monsters, which I, alas, have done more than once.)
But there are plenty of other starting points that a writer can choose, according to her/his background and interests. Tolkien, as we know, started with languages, because languages were his obsession. (I tried this one time, and lacking his background it was a lot of work. A lot of work. To judge whether this was a success or not, you would have to read The Hidden Stars. As far as I'm concerned, the jury is still out on that one.)
During the same class where Tad Williams made that remark about geography and destiny (though it might not have been original to him), he set us all an exercise that used a different method. Members of the workshop were divided up into groups of three, and told to come up with two vastly different concepts -- like a feudal society, and a group of people living in boats on a river -- and combine them into a single culture to be used as the background of a hypothetical story. We had 15 minutes to brainstorm within our groups, figure out as much as we could, and then be prepared to answer any questions that Tad or other class members might ask about how our society would function and survive. The group that I was in chose a post-apocalyptic underground society scenerio (suggested by someone mostly interested in SF), combined with a society looking backward into the past like Numenor during the years of its decline (three guesses who suggested that one).
The groups that concentrated on coming up with a story synopsis, instead of simply laying the groundwork for a story yet to be told, were totally stumped when it came time to answer any questions. (And, which amused everyone, had all come up with almost exactly the same kind of First Contact story.) The groups that followed Tad's instructions were amazed by how much could be accomplished during the 15 minutes. Not that we had worked out and had ready the answers to every possible question that might conceivably be asked -- which naturally would have been impossible, even if he had given us a week -- but that based on what we did have we could extrapolate an answer on the spot. (In other words, fake it, but much more successfully than we would have imagined possible after 15 minutes work.)
Taking this anecdote for whatever you think it is worth, you can draw your own conclusions about what we all learned about worldbuilding during that exercise.
I went away with the idea that this was a very effective technique -- but I still like starting with a map much better because ... well, I did mention that I enjoy making maps, didn't I?
