Cid is 32, Barret is 37 - in FFVII, anyway. It's rather doubtful that Cid perished from old age...

Cid's definitely not looking like a flashback, though. He's got some distinctive changes to his costume in those pics.
[q=zacks_clone]The Aerith/Cloud shot reminds me of FF8. Maybe this is in clouds mind,seeing how all the fog gets rid of anything else[/q]Interesting observation
I'm guessing that'll be an encounter either in Cloud's dreams, like you suggest, or at the Promised Land itself. We know that Aeris can speak to people in their dreams, so that's a possibility...
That setting - the misty flower field - reminds me of the Farplane as seen in FFX and X-2...

Edit: I truly, deeply, sincerely hope that the Turks' suits are actually the same navy blue that they wore in FFVII. They look black in those AC screenshots. I'll be really disappointed if they've been re-designed just to look like generic MiB/Matrix clones.