why is the center point high lighted when I touch an edge to place a dimensions or ask for a relation?
hover over line for midpoint
I don't see this occurring with my version of SW the exact same way you describe. However, I do see it if I am drawing another line by placing the start point on an existing line. That being said, if I had to guess (and I could be wrong) I think this is just meant as a visual reference. That way, before you click to start your new line you can see about where the center point is. Now you can easily find it and snap your new line to the center point of the existing line. I know that if your sketch is complicated and contains many lines (and constructions lines) it can help you quickly locate the center point.
On a side note, is there a reason you do not like this feature? Just curious.
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