I don't want to read about Chakotay's mid-life crisis either as an explanation of his relationship with Seven. Because that takes something away from the Chakotay I like. So I like to think that there were something real developing between them, but it ended before it truly began, because they were suddenly on Earth and their worlds basically turned upside down.
I have marked Mergara's story "Seven" as my fav on ffnet: http://www.fanfiction.net/s/4285380/1/Seven
I have not read it for awhile, but I do remember that it was very well written.