<< AGP Fast Writes (which should really be ALWAYS enabled, unless you really want to have poor performance >>
hmm, Fast Writes gives like a 1% increase in performance. It's true you should leave it on, but having it off won't kill your performance. It used to be unstable, but newer drivers seem to have solved the problem. (referring to nVidia)
Vsync is subjective. Some say image quality is better when it's on, but I honestly can't tell the difference so I leave it off. When it's on, your FPS will top out at what your monitor's refresh rate is set at. In your case that would be 60hz I guess, which is quite low. Do you use Win2K? There's a problem with win2K switching to 60Hz in games...