I did this recently(version 8.1 nor 8.0 were showing all of my contacts, i switched to 7.5, and i can see all my contacts again )
but, to answer your question, i think that emotes are saved, although i can't guarantee it.. personally, i'd recommend backing up the "My Received Documents" folder in your My Documents, i believe that folder stores your conversation logs, downloads, user images, but i'm not sure about emotes...
Also, i'm not entirely sure how copying(not MOVING) the "My Received Files" folder back into My Documents will tolerate an older version of the client.. so..
if you do decide you want to use an older version(i highly recommend against 8.0 and above), back up that folder first!