Is there an "off-line" option?
No. The added services to the game (unlimited installs, online storage of saved games and the fact that you don’t need the game disc to play) require you to have an online connection while playing the game.
What will happen if I lose my Internet connection when I play the game?
If you lose your Internet connection the game will pause while it tries to reconnect. If the Internet Connection is unable to resume you can continue the game from where you left off or from the last saved game.
Will all my saved games be stored online?
Yes! They will be stored both online and on your PC.
I don't understand the game pausing??
Well the save games also being saved locally means utilities similar to sh3cmndr would work, but I'm not sure..