Yes, I just checked again (~ 21:25), they claim to place one stone every 20 s which is supposedly three times faster than the ancient egyptians did. However, they did not place one stone at a time, but several at different positions.
Estimated for 20 year construction time: 2.6 million stones/(20 y × 365 d/y × 12 h/d) = 30 stones/h
Some claim it possibly took only 10 to 15 years.
Yes, this works. However, you can not (or should not if you possibly could?) modify data on partitions mounted by the hibernating OS. If E.g.Windows and Linux are installed and Windows is hibernating, the NTFS partitions can only be mounted read-only under Linux.