1. feature is already enabled for the Desktop version of 2013/Office 365, at least. I've just tried it with a document in SkyDrive.
Dunno about 2010/2007/2003/whatever though.
Should be - regular desktop Office 2013/365 definitely works.
It's already there - just tested it with Word (that came with Office 365 University sub) and Word Web App opening the same document at the same time.
Exactly. There was little point in having the tile on Windows RT anyway. When the next version of Office gets a Modern-UI release, and the next version of Windows (8.2? 9?) migrates even more...
You upgraded from the "Preview" version. Microsoft said right from the beginning that upgrading from the "Preview" version isn't supported and you will only be allowed to do a clean install....