Actually from your post, the only thing you mention that I don't think gets called out specifically is about Aradia, Sollux, Rose, and Dave, and that's only because you're a little confused. They didn't die because they weren't in the game session when it reset, or our universe when it was killed. Remember, the Outer Ring, where the Green Sun is, exists outside of spacetime.
And you say you don't know what was going on with the exiles but....I mean, you pretty much got it. <_< That's exactly what happened. Jack escaped the session that was being reset, came through and slaughtered everyone, and escaped the universe that was being destroyed.
That said if you're still confused or just interested then by all means read the tumblr posts, but they aren't required reading.
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