Seems you have many problems there, and me here with no solutions.
I used the same three word phrase, that's in more than 100 Word documents, and Spotlight found three of them....two from last month and one from 2009.
With respect to Spotlight
and Word
specifically —it all relies on a special file (or files) for those two to have a workable association. Typical location for those items would be /Library/Spotlight/
ls -ld /Library/Spotlight/Microsoft*
drwxrwxr-x 3 root admin 102 Jan 21 2009 /Library/Spotlight/Microsoft Office.mdimporter
If something is wrong with that item (or it's missing maybe... or there are more than one butting heads with each other), then Spotlight won't be able to search Word docs with any accuracy.
Or perhaps there is another .mdimporter file located somewhere else getting into the mix...
mdimport -L
^ will list all that Spotlight is currently employing. [they can even reside
inside apps themselves]
And...
mdimport -L 2>&1 |grep -i microsoft
will filter out all except those which have the string Microsoft in their name.
Other than that, ::shrug::
