During a game, push Select to open the options menu. Choose Key Configuration and hold R1 while pressing the SQUARE button [ten times]. When activated, the Auto or Manual setting should turn red.

To get Extreme Battle, you must complete the game in all four scenarios. When the game is completed, a screen will appear saying a mini game is unlocked. Save your data. There will be a save called "Ex. Battle 1." Load it. You will come to a screen which says Extreme Battle, and you can play this mini game, starting with Claire and Leon. When you beat it with them other characters will become avalible.

When in the stars office go to the desk that says someone was here the desk is trashed.Press it 50 times and you will get an secret photo of Rebecca Chambers from RE1.

Anti-virus bomb positions: I know that the positions of 4 anti-virus bombs are random but in my experience, they could be in four of these positions's:

Ben Bertolucci's cell
Watchman's room
TV Room
3rd floor - Clock Tower
Meeting Room
Guard Room
S.T.A.R.S. office
Sherry's first place of meeting her