Couldn't a Slytherinny parent who wants their child to become powerful coach their child into wanting to be in some House other than Slytherin? Say, MoR!Lucius, coaching his son in all the ways of seizing power, but telling him awful, awful stories of what it was like to be a Slytherin. "No, no my boy, you do not want to be in that House, whatever you do!" Then, Draco under that Hat goes, "No! No! Not Slytherin! Anything but Slytherin!" And thus, ends up somewhere else.

Thus positioned, he does not automatically have to wear a suspicion-generating Slytherin badge, and he gets to be the wolf among the sheep (if he ends up in Hufflepuff or Gryffindor, where there's no Harry and Hermione to match him). Being Slytherin is like being a Ferengi. People already expect you to scheme against them, so their guard is up. But a Hufflepuff or Gryffindor (especially Gryffindor!) MoR!Draco would start out with powerful advantages in his quest for world domination.

Since "rule the world" and "save the world" aren't really that far apart, he probably would have ended up in Gryffindor. If you want to rule the world, presumably you think you've got a better way to run it than the way it's being run. Some would-be rulers might just want the wealth and being able to boss other people around, but it's easier to get that as a cult leader and not have to have responsibility for administering the global economy.

If you want to save the world, you could be defending the status quo (keeping that other guy from conquering the world), or you could see some threat (climate change, death) that isn't being dealt with appropriately, and you have a better way. In either case, you are tacitly assuming that you have a pretty good idea what's best for the world, and act to see that things go your way. Though I'm over-simplifying a bit here, I think there is an element of "who's writing the history?" to whether one's a "Gryffindor" or a "Slytherin." Andrew Jackson: Gryffindor? Slytherin? What about Che Guevara?

My guess is it would be fairly common for partisans of Utopian movements (Communism, Nazism, religious fundamentalism, etc.) to fancy themselves as Gryffindor-type heroes out to save the world, while their opponents and victims would class them as Slytherins. Where would the Sorting Hat put them? :)

Although thinking about it, the actions I remember taking as a ten-year-old seem pretty consistent with you I am today, but I would guess that I am an outlier in this regard.

You aren't. Most people overestimate the amount that people's personalities are likely to or able to change.