This should cover the broad swath of questions and concerns recently raised. If I've missed anything you consider important, please remind me...
Sports:
The sports forum ranks 8th is terms of topics (but lags to 14th in terms of overall posts). Combined the TV, Movies, and Music, would currently only match that (not even getting into how much of the music I would move into the Artistic Expression forum). With 78 vs. 94 topics, I believe Supa is right that the sports fans would spam out everyone else; which can easily be avoided by leaving them their own forum.
While my initial thought was to lump them all in one (basically whatever people are going to watch at home on TV), a sports fan (Supa specifically) requested that it be left separate; both causing me to evaluate it individually, and consider the desires of the users.
And yes, sports fans do indeed consume their product in a different way than say fans of the latest Netflix show. Music fans occasionally do as well, but they are far closer to fans of TV and Movies than of Sports (especially with how much music goes on prime time television now). Also as ethang5 said, "there is a good reason supermarkets place slow moving items in the same aisle as popular items."
I do consider them related enough for the current names of Entertainment Industry, which does put them side by side in the ordering. However, I am of course willing to change names within the proposal before it gets sent up to Mike.
Philosophy and Religion:
I believe at this point them staying separate is an open and shut matter. Religion is ranked #3, Philosophy also does well at #6.
While religion is a subcategory of philosophy; someone starting a philosophy thread about say Kantian ethics, probably doesn't want someone to pull any gods as a Kritik of ethics being meaningless in light of some divine plan. Similarly someone in the religion forum talking about the commandments of their god, would not want someone to jump in saying they should switch to nihilism.
Games:
The current proposal has them separated into two forums based on user needs and interest. Mafia and related ones, is generally for any time users want to play games on the forums. Separate from that, is discussion of video games, people making Minecraft servers, etc.
Right now the Games forum does very well at #4. Most of that seems to be Mafia, with other topics getting swiftly buried. I honestly don't know if there would be quite enough distinct activity to warrant a second forum for games, but I'm open to the idea. Plus the moderation tools while not perfect, would probably take me only about 10 minutes to assign each of the deviant threads over (and yes, with this being my proposal, I would take the work onto myself).
Right now I see someone in the games forum organizing an online game of Risk. This does make me question if I game names the categories quite right. Any suggestions?
Art vs. Artistic Expression (community generated art, music, writing, etc.):
This change is intended to create a single clear repository for a wide range of user generated artistic content (one which the simple name "Art" does not adequately imply). Using music as an example, right now user contributions on divided between two (or sometimes three) forums, with no clear right answer to which it should be posted.
There are of course some threads in the current forum which would be moved to other forums. A discussion about bad jokes at a TV award ceremony for example, would have a clear destination (right now it fits right in at multiple locations)