Question: Does the ruler tool, existing as an item in a fly out menu of the eyedropper tool occur in any photoshop element versions? If so, what are the versions?
No version of photoshop elements has ever had a Ruler Tool.
That's only in photoshop.
One can replicate the Ruler Tool by using the Line Tool and looking at the Info panel to get the measurement(s) and or Angles.
The measurements only show in the Info panel until you release the mouse button and actually create the Line shape layer,