The percentage is easy enough using an array, something like:
_MaxPlanes=Count USSRPlanes
_Count="Alive _x" Count USSRPlanes
_Percentage=(_Count/_MaxPlanes) * 100
Think the syntax is correct, for months I thought the conditional count was some dodgy code someone made up off the top of there heads
Getting the spawned planes flying is a bit more complicated. I'm assuming you want to defend the main Airbase on Nogova?
Try camcreating the plane high enough up, move a pilot into it, then use the action command to turn the engine on. If it's high enough, it should get up enough speed to prevent it crashing?
To spawn groups of planes with waypoints, you need to define the planes and waypoints in the editor, then add the groups to another array. As each group gets destroyed, you CreateUnit your new pilots into one of the empty groups in your array. This way the new planes will use the original waypoints you defined, as they will inherit the original waypoints.
Well thats the theory, its a bit more complicated than that, but I'm a bit pushed for time ATM.