I think it would be nice when your flying offline to be able to inflict damage on your own plane in order to practice "sticky" situations.
Like press Ctrl + D and click on Engine oil which causes that to break as if it were shot, then you can practice landing with the oil leaking and so forth.
Also while we are at it, i think the drones should realistically suffer damage, and not be able to fly with no wings, on fire etc. This would help teach quick shots to see what conserves the most ammo and what is the most effective killing method.