Okay, I got a script working adding more emoticons to the smiley list when posting (and private messages) clientside. MyBB got quite some protections to prevent bots from directly injecting content in the message field, so I had to do it in a different way.
What emoticons do you want added to the list? I'm adding a few skype emoticons already like
![[Image: emoticon-00107-sweating.gif]](http://www.skype-emoticons.com/images/emoticon-00107-sweating.gif)
![[Image: QTDGG.png]](http://i.imgur.com/QTDGG.png)