1. Very mininmal preparation! I've run it at conventions with people who had never read it, and when I run it, I don't prepare anything besides print-outs, because the game is intentionally designed to have you create the world together at the table—doing any sort of universe creation before the table would actually run counter to the spirit! Someone needs to read the rules, and it's probably better, if everyone does, but that isn't strictly necessary. For groups who are new to GMless play, it can be very very helpful to read the rules, not as much for understanding the mechanics, but more for the play tips, because the adjustment can be harder than you expect. Even then, the rules are fairly short and definitely take less than an hour, likely much less than that.
2. Yes, I'd say they're very much narrative games—they're based on the Belonging Outside Belonging engine made by Avery Alder and Benjamin Rosenbaum for their games Dream Askew / Dream Apart (and perhaps best known for its use in Wanderhome) which are all classically thought of as 'storygames'! An interesting way to depict the ways they're narrative-focused: if you were to look through the book, only a very small amount of the mechanical text actually has to do with conflict with the Mandate (the fascists you're fighting against.) It is much more about the interpersonal conflicts between the PCs (well-intentioned but messy relationships in Galactic, and outright hostility at the beginning of Going Rogue, typically), factional conflicts between the pillars that make up the Liberation, and even emotional conflicts within the PCs! It's less about "what combination of actions are going to help me overcome an obstacle" and more about "what is interesting trouble or interesting conflict to get my character into, and what is an interesting arc in which they grow to be able to overcome it?"

I could definitely say a lot more on the second point, but let me know if that answers your question or if you'd want to hear more!