~800 shots (depending on weather/climate/humidity/temperature etc.) and no I believe that may be too weak depending on how fast your shooting. It probably will have enough power to pull back the spring but at the same time if you want to upgrade to a stiffer spring you'll need more power to be able to pull back the spring.
1 mAH = 1 shot usually. Voltage is just the amount of power that is being supplied to spin the gears to pull back the spring.
The battery FAQ explains it a lot better than me though.
ಠ_ಠLess QQ more Pew Pew
READY TO >> RACE