The Futaba gyro with four eyes is not a gyro. It is an auto pilot and there is a big difference.
The gyro will assist stabilization of the plane and make it fly true, but it will not fly the plane as the auto pilots will.
The helicopters that you see doing all the three d stuff would not be able to do that unless they had a gyro called a heading hold. This is generally not recommened for airplanes as it has a few features that can really be dangerous.
Go to rcwarbirds.com and the forum for flying and twins for more on the use of gyros.
Yes, you can use them on areobatic planes. Inputing a command overrides them until you let go. Have seen them on Ultimate Bipe, Edge 540's, cub's, telemasters, mustang's ect.
Good Luck