Hi
"Does that mean that whenever I update or change something on drive C things will take effect on E?"
Yes, it will update the date on the "E"-drive as it was on the "C"-drive.
I would not make a Sublink on the "documents" folder, there I will right-click on the "Documents" folder and select the "Location" tab and choose "move ..." (after making a backup ... :-)
/Jack