Like Italophile, I do not understand why you want to keep Word 2007 when you have Word 2010.
Word 2010 works flawlessly on any files that were created using Word 2007. Word 2010 restores AutoText and AutoComplete. Word 2010 gives the ability to modify the Ribbon within the user interface.

The only reason I ever had it active on my computers was to assist in answering questions and to produce screenshots from it. I never used it for work because it was, in my opinion fatally flawed. I used 2003 until Word 2010 was released.

That said, I used the registry edit method over a number of years to keep Office 2007 from re-installing when something was used. I assume that you made backups of your registry before making any changes. You can restore it from that backup.