You could use the wiframe targeting from 3.5 to show players the damage by coloring the polys. So you would have something similar to the damage displays from the mechwarrior series.
Just an idea...
I'm quite fond of your armor concept. I especially like the idea of damage tolerance.
Depending on the plate's location different kind of damages could be applied to the ship. I don't think it's too realistic that all ships just blow up (there's another thread - and somebody ELSE'S IDEA behind this

- Dereclict ships, your code may help them a lot).
So a ship could "die" several ways depending on where was the killing blow delivered - some systems should be vital, so a true engine failure should be a lot more devastating, while "ordinary disables" should only damage the prolusion not the actual engine core. A fried electronics should also kill a ship - even if temporarly. A certain amount of hull breach could lead to a loss of life support - killing the crew.
So this code may lead to a whole range of improvements.
Large scale hull breach could effectly snap the ship - but some transformation would look cool (imagine a ship with a hull crushed like a tincane :devil:) - although that's beyond this code's aim as far as I see.