Again, I'll ask, where do you think air is coming from that would need to be bled off?
How fast the tank empties is dependent on how much water you use. A 20 gallon bladder tank should have about 6 gallons of drawdown so if it empties in 2 minutes, you are drawing around 3 GPM. If you drew at 12 GPM, it would empty in 30 seconds.
How fast the tank fills back up depends on how much water the pump moves. A 10 GPM pump might not run long enough for the motor to cool down from the heat of current on the start windings. A pump should run for at least one minute and longer is better.
If you are concerned about cycling, put in a Cycle Stop Valve.