Ok I think I found at least one fairly technical way to solve the problem. I realized that Lightroom stores all it's information in a SQL Lite Database catalog, the lrcat file. So with a little help from the following article which pointed me to some details as to where the file was stored and some tools to access it.
I was then able to craft the following SQL Query to return me all the images who have a last history entry that is NOT export, import, or print. That way if I just imported an image but didn't modify it, it would not show up in my list of files that I modified.
SELECT a.name, files.idx_filename
FROM "Adobe_libraryImageDevelopHistoryStep" a
INNER JOIN (SELECT image, MAX(dateCreated) LastDateCreated
GROUP BY image) x ON a.image = x.image AND a.dateCreated = x.LastDateCreated
INNER JOIN Adobe_images img
ON img.id_local = a.image
INNER JOIN AgLibraryFile files
ON img.rootFile = files.id_local
where name NOT LIKE 'Export%' AND name NOT LIKE 'Import%' AND name NOT LIKE 'Print%'
Not a simple end user solution but works for me as a database guy.