Would it be possible to have one window which was completely stripped bare, with just the viewports, and to have all of the subsidiary control UI in a separate window? That seems like it should be doable, and while still not optimal, might be a step in the right direction for some users. Obviously, it'd be better for you to spend your time doing it right, when you have time, but if that's something that the existing UI supports, someone else might want to do that.

/Ella