Bot pilots bombing and disabling runways.

[TexasJG]

If you want your bot pilots to fly down a runway and disable it with craters, you will have to work with them. Some bots will loose focus and go do things other than what you ordered them to do. Also keep in mind the craters are only temporary. They will fade away with time (kinda of cool to watch).
First set up the bomb run straight down the runway and set a G-Attack way-point on the runway at the location were you want the bombs.
Example though, a B-25C-25NA bot will fly straight down the runway and drop it's bombs right where you set it, but a B-25J-1NA may or may-not. It may veer off, bomb and/or attack any enemy aircraft on the ground or other local ground units as it see's fit.
A B-17 bot will do a beautiful bomb run down the runway (quite awesome to watch while waiting to take-off).
A Ju-87 bot will likely veer off on it's on and go after other more appealing targets, no matter how many Article 15's you give him.
Basically a level strategic bomber bot will crater the runway, while other bots such as attack bombers & dive bombers will loose focus.
A work around to use, for example, a Ju-87 bot to dive bomb the runway, is to put a static motorcycle at the point you want bombed, set the motorcycle properties to the Ju-87 bot's enemy army, and then set the motorcycle as the Ju-87's G Attack way-point target. Of course the airfields defenses, if any, will attack the motorcycle unless you time them out.
You must use objects which will stay locked as an enemy object, for example a static light will not work, even though you can set it's army as blue or red, it will not stay as blue or red when saving and reloading the mission
And lastly the disclaimer...(**Disclaimer- unfortunately several bot motorcyclist were KIA or wounded in the development of this tactic.)
And tested using an older version, 4.07m, so some bots may have become more obedient in later versions.

[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.