Thanks,
1) h1 headers to denote OS were implemented to make it easier to convert a page from single OS to multiple OS. If you have the time to change every header level, we can do this.
2) System Requirements move is discussed here: http://forums.pcgamingwiki.com/viewtopic.php?f=6&t=85
3) My original vision for each page was to have each OS under a different heading, with every subsection repeated (different Video Settings, Game Data, tables etc.) but there has been push from other editors to combine the tables together. I don't know what the 'ideal' situation would be. There are 3 options:
a) Each OS with repeated tables
b) Subpages (e.g. Team Fortress 2 (Windows), Team Fortress 2 (Mac), Team Fortress 2 (Linux))
c) Combined information, e.g. Game data with 3 rows for each OS.
Explored in this thread: http://forums.pcgamingwiki.com/viewtopic.php?f=6&t=107