Future Timeline

I think lumping everything under one world (or solar system, or galactic) government is a bit of an overdone trope. Especially based on the UN, which in real life, does next to nothing. If you don't want to write politics and diplomacy, which is understandable, there's quite an easy fix: just set the story in one particular country (whether on Earth or in space) and have most of the action take place there. Similarly, there won't be just one Space Mafia, but many, split among ethnic or even biological lines, that clash violently with each other as often as they do with the authorities.

As for the other themes, they have largely been done, but there's potential to push them in new and interesting directions. Often genetically engineered subspecies or intelligent AIs are fighting to be seen and treated as humans...but what if they aren't? Maybe they have fundamentally different mentalities, social structures, and biological needs that often clash with each other, and this, rather than just random outbursts of ignorant racism, make coexistence challenging. In fact, rather than Bible-thumping racists, a lot of these anti-genemod activists could have very real concerns about the biological Balkanization of humanity threatening its cohesiveness and unity, and fear that becoming thousands or even millions of species will cause endless division and conflict. Anyway, it's basically a way to have realistic yet physically human-like "aliens" and not even have to worry about the logistics of interstellar travel.

As for drugs? Bit of a cliched thing to be smuggling, especially as legalization of drugs is an increasing trend, and possibly the rise of BCI technology may render them obsolete. But there are other legally gray and outright illegal things a futuristic mafia could be dealing in. Maybe there's dangerous and illegal nanotech and synthetic organisms, mysterious rare alien artifacts that are extremely powerful but not well understood, even--if neuroscience and mind-tech get advanced enough--a market for thoughts and memories, with a corresponding black market for illegal thoughts and memories (perhaps people at this Casino Station illegally gamble not their life's savings, but their literal identities!).

What if instead the sentient robot workforce is part of a larger robot and AI ecosystem running parallel to biological ecosystems? Instead of needing food, water, and living space, they vie for computing power, energy, and data, propagating by copying their code (which is limited in practice by scarcity of the aforementioned resources, an AI can't just make a million copies of itself unless it owns a million data centers and a million power plants to keep them turned on) and competing with each other for these items. Physical bodies that allow the AIs to pursue real-world goals without human intermediaries are also a valuable and highly sought after commodity to the AI societies. And indeed, individual AIs or even entire "species" of AI are often confined by physical and/or software constraints and forced to work for humans, genetically engineered humans, or even other AIs.

As they have wildly different programming, they would react to this in very different ways, but their conception of a "union" or "fair labor practices" would be highly diverse and in most cases, very different from how a biological being with a human mental template would approach such ideas. But in general, many of these AIs are still self-aware beings that want to preserve their existence, accumulate resources, pursue goals they find interesting, and interact with other sentient beings (albeit in sometimes very different ways from biological beings!). Yet lack of resources or threat of force from other beings and institutions often prevent them from achieving one or more of these desires.