An armour rating of 2 means that any hit to the hull (which has most anything important) has to be confirmed by rolling higher than a 2 with a 1D10 else the hit is ignored. So a ship with an armour of 2 has a 30% reduction to the number of hits it takes ... pretty effective I think. In theory there is no limit to a ship's armour rating but usually it is not higher than a 10 when a ship should (and originally WAS until it was errataed) be invulnerable to enemy fire?!?!?!?! But on published GDW ship designs for HUMAN warships a value around 3-4 is most common, some are unarmoured. The stated reason given is that human warships are built around the principle of 'hide and seek with bazookas' -->personally I think that is just typical GDW underplay-tested product for you, sensors are too good, armour is too cheap, too light and too effective to not have an armour rating of +8.
UTES stands for 'Unified Target Engagement System' and is the turret mounted cousin to the TTA (Target Tracking Array), making the UTES less vulnerable but more expensive than a TTA --> each TTA or UTES tracks one target within it's arc.
