While all suggestion are useful the biggest take away for me is livesettings. TBH I can't think of how I would use it at the moment but I can see that it could come in handy later.
I'm in the process of writing a pet project using Django and would really appreciate your insights on what packages you find useful (as mentioned at the bottom of your post).
Having transferred companies to both O365 and GApps from Exachange I really have to say that O365 is a horrible product. It is slow and nearly everything about the back-end seems like it was put together in haste.