Nick Bostrom lays out key grounding and terminology for modern thinking about AI & AGI (artificial general intelligence) in his book Superintelligence. David Chalmers is another key thinker, all of his articles are here and information on his books.
Technologies beyond AGI, is really a domain for science fiction rather than philosophy, because real AGI will already transform our world beyond recognition. Certain thinkers who have proved good at thinking about the near & sometimes far future, have been called futurologists. One I find a very interesting thinker and writer is Cory Doctorow.
On immortality you might like the Philpapers archive on immortality. Thomas Nagel champions the view death is intrinsically bad. Bernard Williams argued for immortal life not being worth living. In an interviewRichard K. Morgan said this:
Morgan traces the genesis of Altered Carbon to an argument he had with
a Buddhist at a party. “We got talking about karma and the idea that
if you’re suffering in this life it’s because in a previous life you
did something shitty. I’ve got a lot of time for Buddhism. Among the
predominant faiths, it’s the one that’s the least full of bullshit.
But I pressed him: ‘So I’m suffering and I can’t remember what I did
to earn this suffering? That’s not right, is it, because I’m not that
person?’ And he said: ‘It’s the same soul.’ I said: ‘It doesn’t
fucking matter. What matters is whether you, as an experiential being,
remember it. Otherwise I’m being punished and I don’t know why. That’s
the height of injustice.’”
He misunderstands Buddhist philosophy, because he hasn't integrated it's deconstruction of conventional ideas about the self, with rebirth (not of any unchanging 'self', but of causes and conditions). Buddhist thought has a lot to offer in thinking about different kinds of minds.
The idea human minds will stay uniquely individual in a future where brains can be fabricated is really just a thought experiment, in practice it's a non-starter that would require legal enforcement. I really like Hannu Rajaniemi's Jean de Flambeur trilogy for a more meaningful exploration of the future intelligences landscape. Dennis E Taylor also explores the decay of notions of individuality in the future in his Bobiverse series.
You might like this discussion, on social systems: Are Societies as an Individual Entity, Aware? 'Social systems' & 'power structures' are vague & cover all of political philosophy & anthropology.
I don't think contact with alien minds is discussed enough in philosophy. The Fermi Paradox is a major outstanding issue for science. I like that people are thinking now about whether there could be life inside stars. There is a theory of the origins of consciousness which suggests the surfaces of neutron stars might be experiencing it.
I recommend narrowing the scope of your questions, to get answers that are more useful to you.