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.
To get the Sting DLC for WWE 2K15 on an RGH Xbox 360, you'll need to download the DLC files from a trusted source that offers modded content. Once downloaded, transfer the files to your Xbox 360's hard drive using a USB drive or through FTP if your console is set up for it. Ensure that the files are placed in the correct directory, typically under the "Content" folder associated with WWE 2K15. Finally, launch the game, and the DLC should be accessible in the game's menu.
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