First of all, nothing suggests he wouldn't have used a spaceship just because he's not fully under control or that Bibidi, someone whose powers Supreme Kai has called massive, can't teleport or use simply any other means of travel. This is all an assumption from you, and the fact that Buu didn't kill Bibidi kind of shows why this just isn't something we can handwave.
Secondly, what the Supreme Kai says is that he destroyed hundreds of planets in a few years. That's true. Nothing about that alludes to the distances travelled between, and destroying planets isn't the same thing as traveling between them, so it makes absolutely no sense to mention if Bibidi assisted him except if he helped destroy planets.
Third, we know that Babidi knew about both forms of Buu. So it entirely stands to reason that he has some form of superluminal travel, as even his far more powerful son didn't have remote control over Buu's actions. He could also control Dabura, which would quite possibly necessitate teleportation to get him out of the Demon Realm. There's just as much precedent for this kind of stuff as there is Buu performing a feat we don't see on screen.
The best assumption here is just not to make assumptions based on conjecture.
I will say, however, I am open to something like a possibly rating here.
Assuming he can travel interstellar distances when we haven't seen such a thing is inherently an assumption, my guy. There's no two ways about it.