There is a human empire called the Union, you can see their broadcasts in Ginny's bar. I think we're talking just 25 - 50 planets. Their coreworlds are technological and economic powerhouses though, but they are not the most advanced in the galaxy strictly speaking. The game plays on a station built by them that rebelled and became independent. 10 years ago they did a "moral reform", banishing all futas, heavily modded weirdos, lesser alien species etc from their planets.
Outside of the Union there are plenty of independent planets with human populations, but usually less developed agri words and such. So the futa population, which was subtantial, maybe 10% of the Union but dont quote me on it, fled to stations on the periphery or uncharted sectors (to indies = independent worlds).
I think the vast majority of the galaxy is uncharted, but several sizeable empires are known outside of human space with dozens of planets (Arxadian, Tarnian, Pyrpheran etc). Humans live on hundreds, maybe thousands of planets outside the union, probably most are small colonies. Thats nothing compared to the size of a galaxy though.
I cant answer the technology question that well, its retro sci-fi so in some regard they could be less advanced than our real world (scannig, automatization and drone technologies dont seem to make more manual approaches obsolete in a retro-sifi world), while in other ways its highly varying. Xaphos (a migratory alien species) are so advanced they can phase in and out of reality, Strechers seems to be some sort of synthetic hivemind etc. There are probably many ways of FTL travel, I'm curious too! I suspect the answer is tech is all over the place, but less OP than some other sci-fi out there, so no instant-travel, teleporting and black hole generators.(I hope I didnt say too much BS Void?

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