It's sort of sad, but that really is the only way to deal with NPRs. Just bomb them into submission and oppress oppress oppress until they've completely integrated into your social order.
Could you elaborate? I'm building a mental feature list and i was unaware of this.
Earlier in the thread someone mentioned newbs crowdsourcing designs to learn the ropes. I'd like to take you up on that.
It's admittedly less of a pressing necessity in earlier versions where all NPRs were automatically hostile, but still the best option. If you encounter an NPR it will either be hostile or neutral. Through careful management you can make a friend of it, though that requires a lot of work for nearly no reward beyond the wealth you gain from trading with them. It's far more likely that simply by having ships in the space they consider "theirs" you will drive your relations down far enough for them to become hostile. Even if you raise relations and stay friendly they will, as previously described, happily colonize worlds you're preparing, take over systems in your path of advance, waste mineral resources, and feed thousands of tons of wreckage to any nearby Swarm groups.
If they
are hostile, essentially nothing can be done to change that, and they will attack you whenever possible.
Regarding conquest vs. extermination: Extermination, while satisfying, is incredibly wasteful. NPRs are an excellent supply of wealth, taxable population, free installations, mineral stockpiles, captured ships, shipyards, and any tech/exploration data they might have. If you just smash and burn everything they have, you'll lose a lot of that. My favored approach is to crush their military fleet, use small missiles to bombard any large concentrations of ground forces they might have, and then land several divisions of my own on their homeworld.
Once you've forced them to surrender, everything they have becomes yours.
Everything, including all of their people. Thus, it is virtually pointless to maintain peace for non-RP reasons, necessary to conquer, and highly profitable to enslave and eventually assimilate their population with minimal casualties.
As for the ships, just post the designs here.