Those are really good suggestions. When I develop, site speed and response performance is a priority. I specifically focus on keeping the layout simple and I am also a big fan of avoiding the disorientation of users. By that I mean content, especially navigation, should be consistently in the same location on every page to avoid the "Where's Waldo?" scenario.
I also am trying to provide a layout that works well on mobile devices as well as traditional computers. While the site is still growing, new features and changes will occur regularly. Trying to maintain two or more themes in that situation will be difficult and likely result in the mobile theme lagging behind at times. That is why beyond trying to keep things mobile friendly on the primary theme, I plan to to create a very simplified mobile theme for the site that will work even on older smartphones and will greatly reduce bandwidth once the site leaves beta.
/reality
