I rather doubt that it is actually scanning the file - unless this is the command that it is issuing it is unlikely it would know this path.
If it were scanning the file I believe it would have a small scan window displayed by avast.
Firefox says it tries to have the download scanned by the installed AV - but it fails miserably when avast is the installed AV and firefox doesn't have any way to enter the AV path to have it scanned. This is the most important thing the download manager has to have the ability for you to give it the path to be able to call avast to scan it.
If it fails to have the download scanned as I believe is the case, then 1. & 2. wouldn't have any record of a scan not done.