True enough, but that still doesn't account for the relation between space and time. Considering them two sides of a same coin, if you will, works better. My concept of space is not a vacuum with particles floating in it. I tend to consider it more like a "fluid" together with time. Perhaps the discovery of such "gravitons" will lead to the prediction and discovery of "chronatons", but that is science fiction right now.
The universe of stars isn't infinite. It has a finite, calculated mass. However, if you can conceive the infinity of time, can't you conceive the infinity of space, too?
I think that the farthest we have managed to look is the infrared background noise, which is assumed is the remnant radiation of the initial Big Bang. That would indicate where the boundary of space is, assuming that space began its expansion at the beginning of time, and assuming space expands at the speed of light. Lots of assumptions there. I think I read something about the expansion of space, but unfortunately that's beyond my knowledge. But anyway, I think that the Universe being infinite has more to do with the curvature of space than the euclidean concept of an infinite space.