For the what i'm listening feature, what media player are you using?
If it's windows media player, open WMP, Tools, Plugins, check MSN Messenger Music Plugin. If it is already checked, uncheck then recheck it.
If you are using Itunes, make sure this plugin is unchecked.
For the emoticon 'add' problem, this has happened to many people including me. The way to fix it is to sign in to your .NET passport account here:
https://login.passport.net/ppsecure/uisecure.srf?lc=1033&id=10 then edit your profile so that you are from the UK. Then save your changes and the 'add' should be back.
For customess, what exactly happens, are there any error messages? Try running MSN without plus, sometimes, content fails to install properly when plus is running.