OP, it's nice to see someone thinking about the Galilean moons, and Callisto in particular. All of these worlds are interesting and they fly under the radar quite a bit, so I'm happy to see this post. There was even an announcement last week about Callisto seeing aurorae, which I never saw coming.

I want to first ask about your last point - what do you mean by "the future is in orbit around..."? I understood the second half of the sentence, but not the first.

Re: point #5: Mars is much closer than the Jovian system to the Main Belt, and the vast majority of known asteroids in the inner system. There are some interesting asteroid groups closer to Jupiter (e.g. the Hilda family, or the Trojan clouds that the Lucy mission will be investigating), but Mars has the advantage there in terms of proximity.

Re: point #2: Yes, Callisto is pretty undifferentiated, but not completely so - from what I understand (see papers like this or this) it does have some internal structure. I mention this because I don't think we know enough about weird objects like Callisto (or Ceres, to give the only other remotely comparable example I can think of) to speculate on the ease or difficulty of finding minerals in accessible quantity near the surface. All of our detailed geology experience is from well-structured/differentiated worlds (Earth/Luna/Mars), and we don't know that undifferentiated/messy mantles like Callisto's won't be worse at concentrating ores. I'd be speculating if you asked me about magmatic or hydrothermal processes in such places.

All of that being said, I would humbly like to add one point to your set of arguments: Callisto's location in the Jovian system seems like a huge advantage to me. Jupiter is a fantastic source of magnetic energy and light elements, and the other moons in the system are excellent targets for exploration, especially if you've a base camp on reasonably stable Callisto. Science aside, I wonder if there are resources available on the other Galileans that Callisto may lack, bolstering the overall case. I personally imagine Callisto would be part of a "second wave" of solar system bases/international scientific villages, but this is interesting to think about, for sure. Sign me up for the first expedition!