Ah i'll put it away then. The game is good, spec ops is fun on veteran, though once you've completed the spec ops on veteran, never need to go and do it again. But multiplayer has some crazy fun killing play to it.
No you don't have to purchase through any particular retail chain. Yes there will be "exclusive access" you find it on the front page of InfinityWard.com with a status message of not available so just keep checking back. Also a thought I had it the content it unlock is based on your edition of the game?