no
Yes, but you will need a xbox360 live gold membership card to be able to play them online.
Well, and Xbox360/Xbox lets you connect, and play against your friends online. And you can still have fun in Campaign in some Xbox360/Xbox games to.
It's where you and friends or random people, play online together and you can send messages and also talk to them with a mic.
No, currently the only "online multiplayer" for Xbox is to join one of your XBox Live friends Online Game. Servers, linke in the PC version, are currently not yet implemented.
no
to play two player on your system you do but to play online with your friends you just need to go to online play
no, you only need xbox live if you want to play online
yes
No.
Yes, with a silver membership, all you are able to do is talk to your friends in private chat, and see who is online. Once you but gold, you unlock all the marketplaces and the ability to play online in almost every game that has it. Some of the new EA games have online passes that come with the game when it is purchased new. Those are required to play online as well. If you do not have one there is no need to fret, online passes can easily be purchased through the marketplace or from EA.
No
You can play solo or with up to four friends