Q5.1: How do I bcp null dates?
As long as there is nothing between the field delimiters in
your data, a null will be entered. If there's a space, the value
will be Jan 1, 1900.
You can use sed(1) to squeeze blanks out of fields:
<![CDATA[
sed -e 's/|[ ]*|/||/g' old_file > new_file
]]>