Bot pilots bombing and disabling runways.

[IceFire]

Basically you've discovered the difference between bomber AI and attack aircraft AI profiles. The B-25J has the gunship nose so it will use its guns....even if you have a bombing waypoint at 4000 meters it will still dive down from its previous waypoint and strafe and drop bombs at low altitude. The B-25C will not (for example).

[RPS69]

Yeah! That is asking for a behaviour option on those types when flying over bmbing targets. It actually forces you to rule out a plane from a scenery.