1 -
this way. I wrote a code in "SCRIPT LIBRARY" section. This code makes things automatic for shooting at infantry or vehicles with the good ammunition, what ever the tank could be. It's possible to adapt to your problem if you can say when and/or why you want to change ammos.
So, in other worlds, you need to know or to extract the classes of ammos, the class of main turret and what you want to do.
2 - you can check aircraft ammos as any other vehicle. Do you want to know the current mag or the amount of ammos, or select mag?
magazineTurretAmmo and some other commands can do the trick.