com_affinity exists in MBII Client (OpenJK) and jaMME only. That cvar forces your multicore CPU use certain cores depending on the set value for the game process. The values are bit-field so 1 is to use the 1st core only, 2 is to use the 2nd core only and their sum is 3 so the game uses the 1st and 2nd cores only. And so on with other power of 2 values for every core (1, 2, 4, 8 etc). It's HIGHLY RECOMMENDED to run the game on a single core - it gives much more FPS and prevents unexpected FPS drops. So you better change the value to any value of power of 2. By default it's 1. cg_bob* ones control the gun "bobbing" in first person. r_vertexlight uses precompiled lights in maps so you won't see dynamic lights in game (saber light on walls etc), shadows and the game in general will look uglier but it gives more FPS. r_picmip changes the texture quality. 0 is excellent quality, higher number - more compressed textures. It does not change your FPS. r_subdivisions changes amount of polygons on curved map objects like arches etc. It gives only a few extra FPS. Not sure about values.