Many good suggestions
#5 though, I dont think would be wise, as skype allows access to all documents on the cloud, why make office available to all platforms thus not needing a windows platform to run office?!
I do think they should make 1 purchase, RIM. Buy it for the service and patent. Apply Rim as a service to all Exchange servers, and license it to all windows phones. You have now just made windows phone the default for most businesses. Not sure if the government will step in and demand all phones have access to the RIM service as they have the alternative of active sync. And no business is forced to use exchange servers.
And of course, revert back the start button and start menu on Windows 8.
( I know everyone is harping on it, but you cant revert the start menu back on one image and push it out to everyone, only that one user profile.)
Remember that "choice" is what gave MS the market in the first place. Allow people to choose between the metro and desktop and give them the power. It also helps businesses roll out the OS without much need for training to their workforce. Also it give them a managable image for tablets in the work force. If you provide choice for people in the market, they will choose you.