When I select metrics in the units toolbar, the units on the top left of the view screen are supposed to change as I zoom in and out. That does not happen for me. It just stays at meters. Also the graph ends at a certain point. Can I make it infinite?
The measurement indication on the upper left is in reference to the grid.
If you are in perspektive view or rotated (custom) orthogonal view, then the grid is going to remain the same size, and hence the displayed text will say meters. (The grid is space in meters.)
In orthographic top, side, bottom, front and back view, the grid updates according to the zoom level.