Sorry for the issues. Multiplayer should be back up in the near future. Playfab is fixing the servers now. Will update once it's up.
That seems like a separate issue. Your best bet is to start a new thread in the Support subforum. If you are a Linux or Mac user, then in that new thread, please say what OS version, graphics cards and which drivers you use. If you are a Windows user, upload you DxDiag.txt to that new thread as well. For that, press <WinKey>+R, type "dxdiag", and press "Save All Information...". You can use the "Upload a File"-button on this forum to upload the resulting file.
I'm impressed that you managed to not read "in a new thread" three times. (teasing! ) Anyway, I'd try a driver update first as there is a newer version available for your graphics card. You can get those from AMD. If that doesn't work, really start a new thread in the Support subforum.
There are, but the crash was a very odd one, which tripped no alarms. :\ bascially worse case scenario.
Maybe you need some sort of twitter based heuristic alarm, where if the twitter rage crosses come threshold then there probably is something wrong with the servers and a alarm is raised.