I like it, but that atmosphere would kill humans pretty quickly.
"So independent air supplies are required to be on this station, and a lot of the "apartments" come with built in atmospherics... but from the state of the rest of the station can you really rely on it to keep you breathing?"
Everyone living there that can't survive in the heavily polluted "atmosphere" is basically strapped up with internals, and a lot of living quarters or public buildings have their own internal air supply running through their specific part. I'm still writing it out, but oxygen is treated like how we'd treat water or heating here on Earth, people (depending on which part of the station they're on) have to pay a fee to whoever the local crime lord is that keeps their specific part running for oxygen, as soon as they start skipping payments or can't afford it the filters keeping their place habitable gets turned off.
The place wasn't always heavily polluted, at some point it was about as habitable as any other space station or ship, but overtime both due to the slapdash nature of how the place was constructed in later years and how quickly the place expanded it created loads more problems.