All of the above I guess... that story's not going anywhere though so don't worry about it for now. :P
I have long been considering the First Builders' civilisation and culture for the Story of a Minifigure, so I suppose there's much I could tell you about them. I have already drawn maps for 3-ish faces of Crux, though I have only ever published Galaz, while I know that the fourth has Ninjago in it (the other two I've thought about a little, but not too much). Maybe, I could post those three here.
For the peoples of Crux, there is a lot to say (there would be more if I had defined all of the peoples of the planet). There are Batheians, Makreians, Bat Lords, Mosaic Jesters, Explorien Bots and Bone Suits, the people of the seven kingdoms of Castellar Regnum, the people of Ninjago, as well as some other people of the Oriental type, some Red-haired guys in a big sea, others and there used to be First Builders, but they are extinct. And that's only humans. I am considering other humanoids as well.