There's an option to remove personal information at
Save.  Tools, Options, Security "Remove Personal
Information from Properties on Save".          

The option you describe is good in terms of removing
author name, date created etc.  Our problem, however,  
lies with the metadata held within tracking.  It's
essential that clients are not able to see who might have
authored or altered a version and that that cannot use
the metadata to establish the original author or the
dates of the edits.  I am not 100% that they actually can
retrieve this info, but many of our solicitors and their
witnesses are extremely concerned at this and the rumours
that there are programs available that can interrogate
Word to find this information.