1-There is no multiplayer support in the SF2 series. The old multiplayer support was provided by the DirectPlay module of the DirectX API. Since DirectX 10 does not support DirectPlay and TK does not have the resources to develop alternative networking code, he chose to drop it altogether. It may be years before TK ever supports multiplayer again, if ever.
2-TK did not have time to redo the A-6 cockpit (you can still mod it to be flyable using the old cockpit or use the Razbam addons). However, when you see the planeset and the super detailed cockpits that go with them (F-8 series and A-7 series in particular), you won't miss the A-6 at all.