No two points do not define a line, the relationship between two points does not define a location. Four points actually describe empty 3D space: 1 origin + x,y,z at finite places. The fifth point is located relative to the four.
The area under a curve is reduced progressively by a function that can't be derived by two points. Two points can only discern a finite value. It is only one value. Nothing else is relatively derivable. 1D is a finite valued as itself.
I think you're right (this may be simple thinking) But I figure that location doesn't exist in meaningful terms; It's only used by humans to better quantify something in relation to something else, to make it possible to understand. But I don't think the universe has "location", it is merely everything is where it is. As well, because the Universe seems infinite (to us), location is irrelevant, since everything is equidistant from the end of the universe itself. Although, if something were to be in the center of the universe, and should it ever be proven so, then location could be derived from the center point of the universe... ....Maybe I'm confusing myself, though.