Have you read The Expanse? (it's also a TV show, but the books by James S.A. Corey came first.) It's a great solar-system level sci-fi series with a lot of great worldbuilding about what it's like to be in space, political divisions between people, and also some weird alien stuff. The first book is a bit frustrating because it's the part with the biggest focus on white-man-pain, but if you can push through that there's a ton of diverse characters to love.

(Gideon the Ninth is also very in your wheelhouse, but I assume you've heard of that via exchanges and the like?)

I think you'd also like Can Ci Pin by priest, if you haven't already read it. Galaxy-spanning sci-fi, lots of cool action, a fair amount of political scheming, the main leads spend literal years separated for ~reasons~ (but are both very strong and powerful people in their own way, if kind of morally compromised), everyone's fucked up for various reasons. (It's dude-heavy, unsurprisingly, because it's danmei, but there are some cool women in there.) (cw for a plague arc that gets resolved safely, and there's some stuff that happens that can distinctly be read as torture but I can't remember if it was explicitly framed as torture.)