But fails as described with a scale of 100 (has around a size of 9000x9000x900 then).
Hmm, but i need it this big. That's not fair
you dont need a world THAT big. Start with a smaller project and then go up doing something as big as that.
Alternatively, just make the relative sizes different. The terrain at size 1, and the player at size 0.01, should come out at about the same as if the terrain was a scale of 100.