Actual cutting lasers have a very short range *I think*. Plasma is superheated and would lose temperature very fast, would it not? That would make beam the shortest range, but instantly hitting, making it very accurate and perhaps seriously damaging, being within its range.
Shield defense makes sense, somewhat, but wouldn't a shield and armor be valuable against any form of attack? I mean, armor feels like a core defense, how valuable your hitpoints are, point for point, and shield feels like a secondary defense - perfect when you want to take a hit or two but no more and go unscathed through a fight, but not really the best if you know you will have to tank heavy damage. A fighter would like a shield, while a capital ship wouldn't, mostly?
Missiles should have a homing function and serious damage, but slow attack. The defense against missiles is to avoid getting hit by it through misdirection, making it detonate with shrapnel or blasting it before it can reach you. Missile defense is worthless against any other form of attack, inherently.
Kinetic attacks would, in my mind, be the actual long range attack as it would literally never lose momentum, but it would also be increasingly difficult to hit with as the distance grew, contrary to a laser which would always connect immidiately, plasma would not however, they're really different things, even though I understand why they're both beams. Can't really picture how plasma would behave, I don't know much about it (Like a fireball or ball lightning?)
I think they should rework both the attacks and defenses, bring depth into their functionalities.
That is a necessity, to have combat and equipment be a relevant aspect of the game. Then you could tactically spot vulnerabilities in your opponents defenses, strike with your specialized fleet and move out, or fortify positions with your slow multifacetted ships, keeping specialists off them with your own specialists. Or something, I'm more or less just babbling, because I'm really not sure how it ought to play, but right now all I see is a do or die game where I attack and expect certain losses, with all ships without beam/shield are simply a misbuild. I can't make an intelligent maneuver - I just fall back and hope those who overpower me don't follow, or I sweep in, uncontested, without a need to think it through but to keep my transports out of harms way. I'm sure there's more twist to it than that, but it comes off as shallow to me on a first playthrough.
Maybe Stardock is not focused on having their combat perform, I think that would be a mistake, a missed opportunity.
The trispec system needs real attention to make it a good addition to the game, otherwise it is just a research filler.