Look Speed I would recommend to set at 75% or more, this is how fast your character turns. When playing as an assault unit, you want to be as mobile as possible, and an increased Look Speed puts another Ace in your hand. From where it's at now, I'd suggest upping it a bit, playing some respawn, and adjust from there. Repeat that process untill you become comfortable with your settings.
Deadzone cares for how much you have to move your joystick before the game responds. Set that at zero, that way your actions are as immediate as possible.
When playing as an assault unit, try and keep your crosshairs at an effective level, and this is dependant on your gun's effective range and power. For example, I primarily use the HK 36 as a Seal, and I'm a rusher. When I'm moving I try to keep my crosshairs in a position where I would hit an opponent mid-chest to head when they're within 10-20 feet. I do this because when in full-auto, that's the gun's most effective range.
Check the
-SOCOM 3 RUSHING TIPS AND TACTICS- thread for other useful tidbits.
With rushing/full-auto, I don't try to go straight for the head because it's a smaller target than the chest. Also, with the way the game lags, and F90 BS, you want to hit them with as many bullets as possible.