I think the asteroid belt your thinking of, is the one between Mars and Jupiter. If that is the asteroid belt that she would have to be an inner you would think.
well I think the idea overall is pretty good and if you wrote it I would probably read it. I'm guessing Makoto would already be a salior scout, just be a private detective on the side.
I think that it had it's moments. The beginning of the series the Saiyan and Namek arc was alot better then the cell and buu saga. GT just blew in my opinion.
Why make Ranma run away because his mom makes him kill himself (or herself in this case). I think that idea is used to much in fanfictions maybe you could use something else like Ranma ran way because he couldn't marry anyone now being stuck as a girl and doesn't want to be a burden on anyone. And I...