How do infinite maps work? Can you only have them on x and y or can you also have infinite sky?

In the world editor, you will notice a white square that forms a border of your terrain. the WE will only allow you to edit what's in that square. So, to create an infinite terrain, just drag your terrain out of the square and keep adding terrain tiles to it.

About infinite sky: I have no idea how that would work.. I don't even know how esenthel handles the skybox.

Yeah I know about XY dragging, but not if I can go high in the sky or very deep underground without having to load invisible pieces.

streaming is done per area, so in 1 area everything is always loaded (it doesnt check how high or low the meshes are, they are always loaded, but they are displayed only when they are in viewing frustum)

Well that kinda sucks. Would be cool if instead of being a flat plane, the area would be in a cube.