it will no longer produce a Markdown text file where you choose to compile. Instead that file will be held in a hidden temporary location, to be further processed by the command you specify in the fields below. The file that is created by those commands will be picked up by Scrivener automatically and placed into the designated compile folder at the conclusion of processing.
1) However, <$inputfile> is being set to the file I specify in the Export dialog, and that is the file where the pandoc output is being sent, not a temporary location. So if I use the destination suffix in the Export dialog (eg, .docx), then <$inputfile> and <$outputname>.docx are the same. That my <$outputname>.docx is being understood is shown by the list of applications to open in in the Export dialog (and the output file is opened even though the Export dialog has another suffix).
2) The environment variables I put in the Environment field (in name=value form) are not being added to the environment but are being prepended to PATH, giving, eg, "PATH=Test2=fine:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin" (I'm calling a shell script that calls env).