Very good suggestions!
I'd like to see a good ingame communication for online-playing. It would aid teamplay a lot, if people don't have to join TS. The ingame-comms in IL2 never worked for me.
It would also add to immersion, if noises (enginesounds, guns, etc) would be transmitted, too, as well as atmospheric noise. There is a tool named TS-noise, that adds a background-noise to the Teamspeak-output and the crackling sound from the transmit button. Even better would be raising the noise-level, the further the pilot is away from you and it would also add some immersion, if your communications fail when the radio is hit.
Another thing that impressed me very much in SilentHunter / DestroyerCommand: If people chat, it's handled like they use comms. Sitting in a Destroyer, you can locate and pin down these transmissions. In WW2 this was done, too, by ground units and it would be a great tactical immersion factor.
Another great thing would be a communication like in BF2 or a modified version of the system to give orders to AI-pilots: Simple phrases that in combination send information with a few clicks to other pilots without having to use a mike or speaking English or whatever. With the same phrases in the same categories, they could even be translated easily to the language the player is using.
And a personal wish, that has already been partially confirmed: Kill-markers
