Hmmm. I know this wasn't aimed at me but about the 2nd part, I personally can play it on high no aa @ a stable 30 fps with occasional dips to 27 or so. now one of the members told me thats why I was getting owned alot (my score was really really bad, something like 12k to 30d) so just for S&G I put it on lowest settings.
I have a few points to make here, on low character models seem to just stand out more in distant buildings. Also the shading seems a bit different so they don't blend as well into the background. and it feels like my aiming has gotten a bit more precise.
now I dunno if this is just a placebo effect or not but I figured I should tell you guys my experience anyways, but every since I rarely get under a 0.8 K/D ratio
I personally don't see an improvement but I do feel like it helps, plus I for some reason can't really tell the difference in detail between high or low settings (besides shadows, on low they look god awful)