maybe
yes anything you get from xbox live will stick with your gamer tag but if you are wanting to buy it once for two xboxes that wont work
No.
No.
Depends on the game. Some xbox games are available for download through the xbox marketplace.
Xbox marketplace
yes all profiles on that xbox will have access to the dlc
yes, you can play DLC that was downloaded on a Xbox LIVE profile and play it on a non Xbox LIVE profile
The DLC is saved to your hard drive, but only the account you downloaded the DLC with can access it from the hard drive.
Dawnguard , the first DLC expansion, was officially released for the Xbox 360 on June 26th, 2012.
not 100% sure on this one, but i think you the fallout 3 website has dlc for pc.
Yes, just not any of the dlc
The Uprising DLC is already out for Xbox. Like the Revolution DLC, the Uprising DLC for Playstation 3 and PC should be released in another month. That means somewhere around the middle of May.