Since DRKST didnt answer Ill give my own opinion based on lore and stuff.
Marauder needs a build rate boost - if theyre truly marauders, earning an income from pillaging enemies stuff, they should be a fast building offensive, high ranged race. Swoop in, crush you, plunder and run. Being a super slow building race doesnt make sense.
Collective should have more ships that are capable of capturing, or fewer ships they are incapable of capturing. We put arbitrary limits on what a collective can capture and what it cant because we thinks its unfair to have them running around with some of the more powerful ships, but we consistently forget how difficult it is as collective to get ships where they need to be. Making use of captured stacks, outside of using them as pr bumps when fighting, is incredibly difficult. UC makes it slighlty more feasible by making collective captured ships have +10% weapon, +20% hull, and capture rate is 200% (Kill 100, capture 200). This at least makes collective stacking and specific countering using captured ships more feasible.
If miner are a defensive race that is supposed to rely on being able to outbuild and counter, then they should also get a build rate boost and probably a hull boost (or an increase in multiple hull modifiers at least). As it stands, 90% of the Miner roster is useless because its not as defensive as it should be, and DEFINITELY isnt offensive enough to do anything outside of a handful of ships.
I actually dont know anything about terran.
Viral are great
Tourm OP, Diamond still too op (or maybe miner just sucks and I cant really counter it effectively enough), K class hull mods too OP.
I know this isnt a 3 ship redesign like DrksT requested, but my thought anyways