BecauseGreat suggestions. I'm not completely sold on the nonlinear growth of missile health though. Surely, the more obscenely large a missile gets, the more HP it should have in perfectly linear proportion? What could be done is make so that the size of weapon you need to shoot down a beam-missile is only 1/3 or 1/4 the size of the missile group, maybe even less than that. In essence, you'd need some heavy combined firepower to bring down a capital class torpedo that would realistically be the size of a small frigate, but it would be much more cost efficient than the launcher itself. What happens otherwise is, making missiles above a certain size simply isn't worth it. It feels a little limiting, although i can understand the incentive (a large enough missile is often a one hit kill weapon).
And of course, another issue is often you'd need your main weapons to deal with a very large missile, but they might be set to target ships. To solve this something more could also be done with the AI options: what if you could select Ships, Missiles or Ships&Missiles? The Ships&Missiles option would let you set a missile size threshold above which the AI will switch to killing missiles, and once no missiles large enough are in range it switches back to targeting ships.
A- It's farly rediculous to see a single pixel-light missile tank a main battery cannon fire
B- It's a lot easier to build a bigger missile than it is a bigger turret.