[CakeJumper]

1. Ground aircraft observers and GCI mechanics in scenarios. E.g., the player could receive a radio message when an enemy aircraft formation is spotted by an observer/radar, which is associated with his mission, and the message would include info about the location, estimated altitude, bearing and speed of the formation. And then the player could initiate such a message in response to Tab-8-whatever to get updated info. It's OK if the messages won't have any VA.
2. Improved bullet/round ballistics, including the effects of non-zero angle of attack of a bullet/round.
3. Engine "overcooling".
4. Improve old aircraft models to the level of more recent ones, as much as you can...
5. Ricochet from the ground/water.
6. Since some static planes can now suddenly become flying ones, I think it is reasonable to consider improving the DM of static aircrafts, at least those of them, which can be used for spawning.
7. Improve AI so it might disengage/retreat from a dogfight or not engage in the first place if the fight is not worth it, even if they didn't get damaged and don't have to RTB. E.g., if the enemy has clear advantage and it's not an AI's objective to hold them. Or, when their mission is to escort and they see their escorted planes being attacked, get out of a fight they are in, if they are in one and if they can get out of it, to protect the escorted planes.
8. Key binding profiles.
9. Filter for AI chatter, so you could select what kinds of messages would be printed on the screen or played as a sound.