The moon is a good staging area for rocket launches
Yes, they might actually be able to pay for things from Earth with domestic industry servicing things further out. Nowhere else has an economic "pull" for humans beyond novelty.
Low gravity of the moon and Mars actually will likely cause so many clots that you end up blind within 7 years and dead shortly after and we cant easily mimic or add more gravity.
Source? What I've seen makes it sound like a true medical mystery, at least until we have more data.
We cant spin the moon around faster
You could put a rotating band with a bit of inwards tilt along the ground, which would achieve something similar.
Space stations are also an option; I guess I really should include them. The disadvantage relative to barren rocks is that they have a certain maximum size given what materials are locally available; there's no expanding out over centuries like we're used to on Earth, and you definitely need artificial gravity. You also might need to import a significant amount of volatiles like hydrogen, if it's a near-Earth asteroid. The advantage is the sheer variety of places to put them, and easy access to zero gravity when actually desirable.
I don't know about floating on Jupiter. Nothing really floats in hydrogen, it's extremely cold, and the gravity would be multiple Gs. Venus has pretty much the same gravity as here, as well as the layer of room temperature and pressure gas.
Im still a big fan of Europa and finding out if we do have an alien competition in this solar system.
Don't forget robots are an option, if we just want knowledge or to mine various rare-on-Earth substances.
In the long run, interstellar travel seems possible, although we'd have to be very patient.