No, you can modify your PD weapons to be more accurate if you want. And point beams are fail-proof dead-on accurate.
You could make your plasma weapons, yes, but as I have already said, just about everything else would work better and do more damage for the amount of energy spent.
Oh, I understand that you can make everything super-accurate when you make custom stuff. I'm just referring to how the vanilla content works, since thats what I assume is the depiction the game is going for. Subsequently, ship designers will have to follow that depiction if they want to make balanced things. Personally, I'd set it up so ships fired a lot more shots, but also fired a lot more point defense. But I guess at that point we'd have to worry about lag with so many shots onscreen at once, as well as things just being confusing.
As for the plasma weapons, I acknowledged that there are probably simpler ways to do the same amount of damage. Plasma anything is just kinda odd, as far as weapons goes.
I never actually fleshed it out, but the conceptualization for the graphical style of the game is that it's an enhanced image that is displayed on the tactical display in the CIC of your flagship. This accounts for beams and the glowy ships. Also it's plausible that the tactical display compresses distances into a useful representation, since Newtonian motion has very little meaning if not taken in relation to other moving objects.
Ah... okay, yeah, I can live with that.
Though I'm still bothered by the walls of asteroids we seem to encounter, even at supposedly reduced scales.