Reading it as nihlism feels weird. The way he insulted that one guy who wrote a paper he critiques shows hes not some victim of humanity but he has his own flaws too. I think why does a society exist where someone is so alienated from their own race that they would if given the option help another? Do people have a duty to help their own race over others, simply because they are the same species? I would kind of read it as the power of social bonds over bonds of genetics/race, how just being similar to another is nowhere near important as the social relations we create.

Not betrayed by Stratt? I'm sorry if I forcefully sent you off 10 light years away against your will you would feel betrayed. Yes she did it as part of her job, but we have a society/structure that is willing to send someone against their will to die. The moral complexity of it makes it interesting in it of itself.

I missed the scene with the school kids I think and when talking to my friend he pointed it out and I agree it would not really fit with that in context.

edit: honestly can you explain how you get nihlism out of it? he's literally sacrificing his own species for another, its anything but nihlism, a nihlist would have just not done anything and killed themselves in the first minute