My feeling is that the ransom note was written out of boredom, of waiting for the night when Jonbenet could be gotten. (Remember the paper missing, perhaps scrap), To me, this note was written by a young white male, not particularly educated, part of the media culture - with references to movies ("don't try to grow a brain"). "A small foreign faction" is a sign of a not particularly sophisticated individual, repeating what he has read somewhere else, in the movies or TV probably.
I also believe that the actual molester may have been an accomplice of the note-writer (who may be dead) so don't make too much of comparing handwriting.