A: YES!
With the recent roll out of the free upgrade from Win 7/8.1 to Win 10, we finally got around to upgrading one of our test machines to Win 10.
- We chose to use the Media creation tool for the upgrade since after a couple hours of 'waiting' for our reservation for the upgrade to Win 10 (which we believe is merely a background download of the upgrade), we decided to try the Media creation tool route instead to downloaded the installation. The Win 10 upgrade downloaded in around 30 minutes via the media creation tool route.
We will continue our testing over the next few days however it appears the Win 10 upgrade is a painless upgrade which includes all required components.