Yeah GR chat and other in-game lobbies rock! I actually do enjoying reading it. Setting yourself to busy though would be grand, especially when your streaming and get trolled in heavy whisper spam abusive stuff.
We totally needs this. The amount of times I have experienced abusive spam when I am streaming and to others is ridiculous.
One more thing I just realised. Since everyone is allowed only one profile why don't you have an option to never play against abusive players even in ranked games. Let's say you played someone like the sageofsixpaths or whatever and you never wanted to play the guy again because of his unpleasant behavior. This option would be perfect for that.
Also in general there should be an easier way to report someone if they are abusive or if you suspect them of cheating. Originally people would have to go onto GR and onto the fair play forum if you wanted to report someone. This was very inefficient. Instead I would suggest putting a report player button in the actual in-game interface with a list of sub categories such as 'suspected cheater' or 'abusive language' and then a short section for the reporter to detail the suspected offender.