Regarding the third and fourth from the last counts, I gotta agree with you, tsuwm, on strictly logical grounds. I think it is a misapplication of the common third (or fourth, as the case may be) from, e.g., the right where the one on the right could be said to be the first from the right, defining the right as the right edge of the frame of view. Saying the last seems to me to be explicitly referring to the last item and not to some defining point beyond the last item.