Too many planets

[apache]

Well, my theory on Gas Giant colonization is that they are in some sort of massive space station that orbits the planet within the atmosphere. This would be quite feasible, especially if there was some sort of anti-gravitational technology. They could fly around in aircraft or whatever to get from place to place.
I think the difference between the domed Versions of all the planets and non-domed is basically the life forms would need some sort of breathing apparatus to survive outside the dome, while in non-domed planets, they would need simply an environmental suit to protect them from the hostile environments. This would allow them to get around the planet much easier if they did not need to bring their air with them.