Jason,
that's definitely a bad place for any user modifications. These are the original e-smith files that you are going to change. No control for you (or them) to separate original files or content from modifications.
Have a look at the e-smith.org website. There are pages with very good explanations about customizing the system and one example is exactly for Samba modifications.
Basically you will copy the standard templates in a new directory and do all your modifications there. Once that (copy) is done, I would *not* put my own share definitions into the 10globals file. That file is for Samba's global definitions. I would create a new file (ie. 61myshare) for your new share(s) but that is just my personal preference only.
Regards,
Michael Doerner