I think as you say if we can terraform Mars we should be terraforming earth first. And if we’re that advanced there might be reason to choose Ganymede, Titan or even Venus over Mars. Venus sounds crazy but it might be easier to change a hostile atmosphere to a habitable than build one completely on Mars. Venus is just a bit less gravity than Earth. Low gravity is a problem on those two moons (but also Mars) but also I think they have magnetic fields which might be good (which Mars and Venus lack).
Dr Eleanor Janega was saying on a podcast that in the Middle Ages the colosseum was over grown with ivy and plants, with wild animals etc. Which would have been cooler. But yeah where you do draw the line on maintaining it versus creating a new thing.
Straight just used to be a synonym for heterosexual, as opposed to gay and homosexual. But I do think it kind of has broadened to be the opposite of queer, or a synonym for cis het.
So yes in the old sense, perhaps no in the changing sense. A heterosexual t4t couple still challenges cishet gender norms etc