Don't uncomment unless you have a mod that explicitly requires it. Forces the game to make NPCs' face textures as you play, fixing any 'grey face' bug. Don't enable it unless you've installed the game on a SSD. Whether the game stores cache on the drive instead of RAM. This setting can easily waste RAM, so don't raise it over 64.
Anymore than 9 would be excessive, even with interior expanding and/or NPC adding mods.
The game engine can only handle 2 threads at a time.
Setting it to 2 generally helps stability and performance. Tells the game the number of CPU threads it can use for things. The other 'bUseThreaded' lines are either not read by the game at all, or don't make noticeable difference. Let's the game handle AI processing a little easier. Probably unloads during loading screens, but not 100% sure on specifics. They hide an invisible loading, so this doesn't mean you'll instantly have mouse control. It's pretty easy to tap Escape, but it doesn't hurt to save yourself a tap. Turns on or off the intro movie on a new game.
