1. CIWS, as the name implies, is a Close In Weapon System, that protects the carrying ship only. It fires at point blank range (I belive at 1000km, as it has a build-in 1000km range anti-missile sensor and fire control)
2. The tracking bonus applies, when you can _see_ an enemy missile closing in. To get the bonus, you need an active sensor, that can see the enemy missile as far out as possible. Your Missile Control System does not come into this at all.
3. As the range of the CIWS is restricted to 1000km, you need a 1/10th size firecon of a 10.0000km fire control, but only a 1/16th firecon of a 16.000km fire control, therefore, the CIWS with the better firecon will be smaller.
