Well, the sys_ command does basically nothing except define the top of a graph, nothing that affects performance.
r_texturesStreaming 0 Is an FPS saver and it makes the game look much better to boot.
However, its very specific to your videocard. My videocard (8800gts 640) has a bunch of memory, but the memory access is mildly slow. Normally, the textures go through a level of detail process, where it becomes more and more defined as it loads more of it, and it decreases the amount of memory space needed on the card for textures. However, that is a lot of loading and unloading of textures and is not kind to the video memory. When this command is set to 0, it forces all the detailed textures into video memory when you load the map, and you only see those. Previously I had stuttering when moving fast, and its loading and unloading textures all the time. No such issue now, silky smooth.
s_maxchannels you know of already.
And the binds are what are talked about in this thread. tapping 7 inverts my mouse (inverting the invertedness for aircraft, the double negative makes it noninverted) and tapping 8 puts it back to normal.