1. Starting in safe mode will make no difference, the settings would be the same.

  2. Can we deal with the question already asked (what was the malware name of the detection), before pushing on to others as this is I believe the more important issue. This makes a difference in what action should ultimately be taken.

Personally I don’t feel it is a good idea to remove the archive if the action fails, because an archive file in most cases is inert.

  1. There is nothing to be unduly concerned with as the file is inside an archive/installation file and would only become an immediate risk when unpacked from that archive/installation file and then executed before there is an immediate risk. As you are seeing simply scanning the archive/installation file detects this, so it couldn’t be extracted and run without avast intervening/alerting.