Thanks! I've restarted once already (which temporarily fixed the 'can't pin to Start screen' issue that seems to be a problem) but will try again...

I was trying to figure out why the Start screen looked odd--and then I noticed the app icons in the tiles are about 1/3 the size they were in Windows 8, so you've got (for example), a tiny W for Word...

Added my iCloud mail account without issues--but it's not visible in the list of accounts. When I try to re-add it, the app says it's already there. Do I need to uninstall and reinstall Mail?