Ooh, ooh, Great idea. I would immediately use position: absolute and rearrange the page so the stuff I don't want to see goes away.

Things like "Time per move", "Public game", "Board size" "Layout-columns", weendays - these are all sooooo irrelevant when I'm playing a game, even "Game Id".
I'd move the [Move] button so that it's actually visible on the page and change the size of the message area, and, and, and....

But all that would need plenty of elements to be given ids. A good bit of thought would be required to choose which ones can be played with. Or just give 'em all an id. Yeah, yeah, yeah!