Yeah, I forgot the pilot firing wasn't just small craft, which is where you normally use it.
I'm not a super expert on ship combat, it has never really interested me that much. But I'd be pretty leery of cheesing the fixed mount rule like that and would only allow it if using the vector combat system and actually have the mount defined. You don't have any fire control for target designation other than the turret camera or whatever. That's the whole point of not having tonnage assigned to fire control. Turrets are what let you elide the facing issue in standard combat. Saying that firing off a smart missile in a random direction will allow it to find the target you want it to find on its own seems a bit of a stretch.
Vls missile that exist today work like this, you will recall that missiles are not fired from the hull under power, they're ejected, iirc by compressed air?, There is, for a self maneuvering munition, no need for it to leave the launcher directly towards the target. This is how modern naval missiles work, this is how most land based cruise missiles work, this is how some sam's work, this is how mlrs with guided munitions avoid counterbattery fire
You make a lot of statements about what one would certainly do designing a ship, but no ships in actual publications are designed like that. With fixed mounts, with no power for the jump drives (except in references to ancient low tech practices that don't apply anymore) and merchant ships with the pilot doubling as gunner. But even if that were all as normal as you say, I don't think missiles are the way to go.
I mean, many of the standard ship designs also don't work very well, ie, traders that don't make a profit using the trading rules as written, warships with low thrust, armor/protection and short ranges weapons, etc, I don't think this is necessarily the best line of argument. I think the idea that a commercial freighter wouldn't be specifically designed to cram the most cargo in it's hull and keep costs to a minimum doesn't make a lot of sense to me, I can definitely be#, convinced that different designs would accept different compromises but like
A single turret beam laser costs MCr0.7 to install, contributes trivially to maintenance and otherwise has no operating costs. It costs 5 power. Considering a Far Trader has 90 power, I don't think its difficult to imagine that they couldn't come up with 5 power in a combat situation. Yes, the pilot takes a -2 to hit. But the weapon is +4 to hit. It is a turret, so there's no question about facing. The fixed mount missile tube costs MCr0.85, uses Cr20k every single round it fires and can only fire three times unless you have a gunner to reload it (and dedicated tonnage to carrying to a missile magazine). And it is going to roll to hit at only +1 (for the smart trait), assuming it survives the pirates' ECM and point defense actions.
The whole idea I was proposing was that you could use missiles instead of turrets for ships that expected to need to fight only rarely to save a not inconsiderable cost in terms of crew members (recall that the pilot can only fire 1 turret but any number of fixed mounts) and tonnage for additional cargo space
Also a singly mounted missile rack can fire up to 12 times before needing to be reloaded
Also recall that only ships of 7500t or better have ecm by default as of hg update 2023
If you have any other person on the ship be the turret gunner (the steward, the cargomaster, whatever), then you still are not increasing cabin requirements AND you can now use that beam laser for Point Defense yourself if your opponent has missiles (you have to be designated the gunner to take that action Pilots can't). Oh, and the pilot could theoretically take the "Aid Gunner" action, though a merchant ship probably doesn't have enough thrust to do anything except evade or try to open range.
Fwiw this also requires cross training, which you were previously turning your nose up about
If you increase the number of missile tubes in your fixed mount, then you are further magnifying your costs over the beam weapon (MCr0.25 per additional tube, plus the ammo cost). You might want the triple beam turret if you think you are going to go up against an actual paramilitary ship like a close escort, patrol cruiser, or corsair that has armor in the range where +2 dmg and +2 point defense might matter. But if that's a problem, you aren't likely operating in any kind of patrolled area. A lot of pirates, especially in patrolled space, are converted (or just opportunistic) merchantmen, so little or no armor. Most merchantships, imho, would have a beam laser and maybe a sandcaster. Both of those being useful for staying alive long enough to jump, which missiles do not unless they happen to hit. Which is not particularly likely. Even if it survives ECM and PD, a missile is only about 50/50 to hit and it doesn't stop the shots the bad guy has taken at you.
You don't have to pay maintenance on missiles, so there's that
Again, refer to the scenario I have repeatedly described for the ship I'm proposing but you continue to ignore. The point is that you don't hang out in places where pirates that mean business can hack it, and you make yourself threatening by packing an armament that's hazardous to the craft you were describing. The ship I'm describing works particularly well as a fairly large bulk freighter
Obviously, there is no definitive answer to this because it depends on the assumptions made about how piracy works (how frequent, what kind of ships pirates have, etc) and how ships are designed. But the designed ships in published materials use turrets and funded or nearly funded jump drives. And the encounter table says "Pirates often use armed free traders or even scout/couriers."
You will note that the scenario I'm describing is in line with this
