Since stuffplug doesnt work I REALLY LOVED the option to be able to type w/e you want with lines above and under ( like when clicking nudge but you can type w/e u want inside)
Messenger Discovery has both (!fakeinvite and !error), except the !error command is somewhat crap, someone who's name I can't remember off the top of my head has made a command collection plugin which has a better one.
I'm using an old script to achieve the chat window icon reflects contacts' status.