re shiny hulls and heat plates:
Yeah sure a shiny hull will be pretty easy to spot, but for defensive jobs it might be worth the extra protection.
It all depends on how powerfull the lasers are. Are they more for harassing, shooting at sensor arrays etc or are they powerful enough to act as main weapons.
Example: A ship defending something stationary. You know the ship is there so there isn't much of a point being stealthy. If that ships hull can take the energy of a 1 second laser burst before boiling away completley, the difference in time it stays alive is rather big if you go from 10% reflectivity to 90% (1.1 vs 10 seconds).
But all this might be moot since you have energy shields
I guess it's a choice one have to make. choose what's important be it missiles or mass drivers or whatever and then adapt the tech accordingly
Heatplates:
The realistic thing that everybody forgets (or choose to forget
) is, all form of powerplants generate heat. Even assuming 99% efficiency, it's still a lot of energy to get rid of. And in space, big ass radiators are the only way (venting plasma etc is no good as you run out of plasma sooner rather than later
).
So, you need to run at least some parts of the hull pretty hot. That could be used as a tactical element. Destroy those parts and your enemy needs to power down pretty soon. Also, it makes it impossible to be stealthy when running the engines/lasers/particle accelerators as part of the ship is glowing in the infrared or even visible spectra. And after a battle/manoeuvring the ship needs to cool down before it regains its stealth.
Aah, the possibilities of geeky scifi battles
And the best part is that this is just normal physics (I'm including your relativistic stuff here). No startrek modulate the upper EM bands, use the main deflector dish to generate a tachyon pulse bla bla that makes no sense to anyone