For one, there's and FPS option under the "movies" tab.
For two, If you're FPS dies even after playing around with the FPS options, you can just hit F9 as soon as you die, follow the hacking, glitching, abusive admin, whatever around. Then stop recording, or make sure that you play in Battle recoder servers and try and figure that out. For the most part, screen shots work. I.E. The dude that posted this could have just taken a screen shot of him being kicked for "c4ing vehicles," although that could be mistaken for jihad jeeping.
Anyway, when I use fraps, my fps goes from 30 to 30. Running a radeon 9800 pro, custom graphic settings. Just selected medium, turned everything related to shadows and lighting to off or low, and then changed view distance scale to 100. Hope I helped, but I'm a complete noobie to all this techie stuff. Just plug and play, and fortunatly have limited to no problems. (minus ea glitches that force me to get fraps and take screenshots, but hey, the worlds not perfect).