You don't have to buy it. Just download it for free
None you have to buy the game the legal way.
No
Yes, a keyboard is necessary to play Modern Warfare 2 on PC, however you cannot use a keyboard to play Modern Warfare 2 on PlayStation 3 nor Xbox 360.
no but your just going to have to look on modern warfare 2 online
It not a part of Call of Duty Modern Warfare 2
Not really. The campaign will still not make sense, even if you played the first Modern Warfare.
Go to the main menu and select Multiplayer... Then Play Online...
No they are two diffrent games.
Yes, it's on ds which you can play on dsi, it is calledCall of Duty: Modern Warfare Mobilizedf
You don't play...
and strings
Yes you can but it is a series