Have you looked at the insert required tags set option? The option name is set addrequiredtags which you can find in the online help's index. Turning this on will enter any required tags. Now if title or classification are not required, then there is a problem. Of course now any other element that has required tags will also be added, so there are some drawbacks. But this may be easier than trying to make the ATD file work.
Remember one thing about the ATD file. If you make changes, you MUST recompile your DTD or the changes won't show up.
I haven't messed with an ATD file in awhile and I don't have anyother versions of Epic other than 5.1 installed on my system any longer. So I really can't help on the ATD functionality.