Long reply... yeah I tend to do that now and then!

As for windows and doors I would say this: If you are going to use industry standard windows and doors, then there is no need to lay them out with the wheel at all. I laid out my windows because I plan on making my own, and I like the proportions of that particular window. I don't see any difficulty in framing in a standard window or door.

I can't say for certain, but I would guess that you could use the wheel just fine to find room sizes if you wanted. That said, there's no reason at all why you would absolutely have to. The wheel may be the most useful in laying out the overall proportions of a building, after that you could use a measuring tape all you want! Unless you are doing like I am and am making a point to use only medieval techniques and methods throughout. To use the wheel for everything may have little real value beyond novelty or a sense of accomplishment.

The roof overhang on my building was not calculated based on location, It was designed as it was to emulate a specific architectural style.

Keep up the questions, bmike (and others too) these are the things we need to ask!