Nope, it's a single player game.
Yes.
Probably, you can hack anything.
You can't download Fallout New Vegas add-ons, you have to buy them with REAL money. If you were to download them online if you have a PC, that would be considered illegal.
seeing as your using the game for personal use then yes it is perfectly legal
Occasionally Fallout: New Vegas will freeze, but not as frequently as Fallout 3.
fallout: new vegas 2 I've heard.
Fallout: New Vegas
Fallout New Vegas is the fifth installment in the Fallout series. It is for the Xbox 360, PS3, and the PC.
Fallout new Vegas
No, you can't get married in Fallout: New vegas, but you can have sex in the game :)
fallout new Vegas will be on PlayStation 3 and Xbox 360
In my opinion, Fallout 2.