For a preliminary investigation of the possibilities, the following scripts and posts may be relevant.
_MarkCurveStart
_MarkOpenCurveStart
_MarkCurveEnd
_MarkOpenCurveEnd
So the endpoints can be obtained.
_PointCoordinates3, currently displays point coordinates for one point. Perhaps could be modified to compare two points, within a tolerance distance,
to see if they are identical to n decimal places, another tolerance.
I guess zooming way in runs into pixel display issues?
Does a closed curve have identical start and end points, or is there a tolerance?
Do two curves intersect, or just pass very close together?
