buy the pro version for 37$US for longer than 30 seconds
No, and neither should you if you download it from http://www.fraps.com
No, The battery size determines the Rate of Fire or how fast it shoots. The fps is determined by the spring.
No it does not. The fps is controlled solely by the spring. Batteries are mainly small types and small types are either 8.4v or 9.4v the difference is the higher the voltage the better the fire rate.
FPS can stand for 1. First Person Shooter 2. Frames Per Second