Enough said. Love it.
I do agree that it is far more realistic that the majority of "manual labor" (it's not REALLY manual, since you're slouching inside a cockpit leather chair) will be preformed by androids rather than "people" in the future.

I do however have to mention that your initial reservations about how illogical it would be to have hired npc's that then you can just throw to their deaths without them complaining, are utterly wrong. This happens in real life all the time with real life sentient self-concious human beings. Mostly in wars.
We see how few powerful people (leaders of nations, generals, officers) can directly order subordinates to their deaths, in a futile attempt at a 1/10 odds victory.
This is certainly not anything strange (sadly) or unrealistic, there's no reason to assume it won't happen in the future either, especially as populations explode exponentially with several colonies all housing billions of individuals. Not everyone can be a CEO or a general, not everyone has power or real "choice" in their lives. Some are simply forced to accept orders, or face exile and starvation from society (and real starvation at that, especially in space!).

That said though, the android idea is probably the most friendly one, and one we can happily abuse without remorse.
Go my fellow soul-less androids, throw yourselves into the fire for my glory!
It has a nice ring to it, it almost gives a Total Annihilation feel to the universe, that simple terminology change.
A cool sensation that most of the ships around you are just "emotionless artificial plebs", iRobot style. But that there are big players behind the curtains out there pulling the strings.

You could even have gameplay mechanics around that, where literal swarms of fearless tiny ships obey the npc commander without question.
Drones from Stargate SG-1 anyone?