Yes, but the software only works on Windows systems. However MacOs and Linux users can also use this case but only with stadard preferences.
In various tests was shown that a HDD can cope better with software-sided start-up and shut down than turning power on and off. This has nothing to do with MTBF (Mean Time Between Failure).
Yes. Of course they depend on the power managment of the HDD and on the basic consumption. The data may vary from HDD to another.