Three more balancing things I am a bit curious about. The Sunder is horrible in terms of defense. In vanilla it had this particle accelerator weapon to balance this out. Here it seems to be missing. And the second thing is the Medusa. Its armor rating is incredibly low. Lower than that of some heavier fighter wings. Maybe make it a bit higher. And the Eagle (Sci) has this built in hull-mod that lets you passively vent 50% of hard flux. It might be a tad bit too strong, though I can't say I don't like it
Regarding armor maintenance nanites: I would make it so that venting takes 2-8 times as long to balance it out depending on hull size (bigger ones take longer), because else it's too strong for ships with super tough armor. Though I think the AI may be too stupid to use it properly. If they use it when they would normally vent, they could disable their ship for too long and it might leave them in a bad spot. There should also be some AI loadouts for a few ships with this and shield shunt installed which would need some playtesting.
Regarding carriers I would make it so that some carriers then give an ordinance discount to gunships and bombers, instead of fighters and interceptors so that some carriers are thus more specialized towards them. Epiphany could use that for example, because it has a recall device and can quickly restock bomber payloads.
Well my idea of the tech levels is that low tech should have bad shields, but a lot of ballistic fire power, very heavy armour and hull integrity and maybe some shield alternatives. Mid line is more about good maneuverability and mediocre shields and still good firepower and high tech is about phasing, special weird ship systems and very good shields and low armour and they should lose combat readiness quickly.
Maybe you could make some versions of low tech LPCs that cost as much OP as high tech LPCs. They could have very fast replace for example. Or you could just add more ships to the low tech wings and increase their OP. Talon wing with 6 fighters per wing instead of 4 for example and call it Big Talon Wing.
I have one more question: I modified the file with the Shield Shunt like you said and it is still nowhere to be found. There is even a mod I use, where you can look which market has which item currently and there is still none to be found. Can I modify a file somewhere, so that I have shield shunt from the start or that I get shield shunt in my current game? I wanna test it out a little bit.