Basically, what I'm trying to say is "We can't guarantee we'll always be able to play keep-away, so something strong enough to survive the occasional hit, fast enough to evade most threats, and agile enough to stay all but the fastest ships, is probably pretty good." We can refit this down the line when we have some more Research done to give it a bit more flexibility and maybe squeeze a little more speed out, but this'll still be faster than anything but a Cobra in the Imperial arsenal, and a Cobra is famously weak outside of their torpedoes (Which are basically useless against escorts that don't just sail right into them).
Honestly I think you're wrong about 'we can't guarantee it'll never get hit' bit. You can never guarantee a combat-ship won't get hit, yes, but this isn't a combat ship. The only instance where a Destroyer Pathfinder could ever conceivably come into combat range would be if the fleet it was leading was ambushed by mobile forces almost instantly upon coming out of the warp, which (barring Precognitive Bullshit which we couldn't prepare for anyway) is AFAIK impossible, because warp travel doesn't have 'fixed' emergence/departure points; you can drop in and out of the warp anywhere along the border of a star's gravity well. As such, upon leaving Warp, any enemy formations should be at least several light-minutes away, which translates to hours of STL travel even at something like 0.3 C, which would be more than enough time for a max-acceleration Pathfinder to detatch from the Fleet and just start accelerating away from any threats at max-speed, even if it has to head out into the Long Dark to do so.
Your design, by its description, is intended to stay with whatever fleet it is guiding, which means that (even if it stays with the Libras) it
will be going within dangerous range of combat-I.E functionally real-time operational ranges. My proposed design wouldn't-it would be staying more than 10
light-minutes from any threat at any time, constantly changing course and vector so that low-emission 'stealth' ships can't try and ambush it via momentum-based intercepts.
Also, yes the Cobra can't hit your design with its torpedos, but Cobras also have a macro-cannon turret, and our Pathfinder has nothing. If Cobras can isolate your design, it doesn't matter if they have shit firepower-they have more than an unarmed frigate that can't outrun or out maneuver them, and at that point, it's only a matter of time.
I'm just gonna propose my own plan and design:
[ ] Plan: Build-Up And Guidance
-
[] [General] Develop The Federations'...
--[] Military Industry III
-[] [Military] [Construct] A Warp Ship
--[ ] Libra-Secundus Class Light Carrier
-
[ ][Military] Design A New Voidship Class - [Destroyer]
--[ ] Polaris-Class Pathfinder
And my proposed Destroyer-Scale Pathfinder
[] [Destroyer] Polaris-Class Pathfinder
-[] Length - 1.200 Meters (+2)
-[] Width - 200 Meters (+2)
-[] Acceleration - 8 Gravities (-1)
-[] Armor - Thick Single Hull (-1)
-[] Shields - One Array (-1)
-[] Weapons - None
-[] Equipment - Superior Gravimetric Engine Calculations (-1), Hymns of the Machines (-10)
[] Andromeda-Class Pathfinder Ship
-[] Length - 1.600 Meters (+1 DP)
-[] Width - 350 Meters (+1 DP)
-[] Acceleration - 6.5 Gravities (-1 DP)
-[] Armor - Single Hull
-[] Shields - Three Emitters
-[] Weapons - Unarmed
-[] Equipment - Superior Gravimetric Engine Calculations/Hymns of the Machines (-11 DP)
Alectai's proposed pathfinder design for comparison.
My proposed destroyer is faster, and has better armor and shields, though admittedly a lower overall health pool. However, considering I intend for doctrine surrounding this vessel to be that it stays several light-minutes away from any enemy combatant at all times, as opposed to his that would have it remain with whatever fleet it is working with, that shouldn't really be an issue.