1. Since this is a limited download, there is actually a download limit, I checked on their forums when I couldn't download it.
I have however just been back and the download link is active, so I have downloaded it.
2. Whilst I have the Pro version which as a resident will have the SAS service running. For the free on-demand version, when you set it up if you elect to have SAS in the explorer menu then it presumably has the service running to be able to run the scan.