Thanks for sharing your updated script. One small note is that in line
50 the name of the package needs \ to escape the SPACE
character/usr/sbin/installer -pkg /Volumes/Install Google
Drive/GoogleDrive.pkg -target //usr/sbin/installer -pkg
/Volumes/I...
No, @cbrewer has the script downloading the Extended Support Release. I
think you'd want to use the canonical download url of
"https://download.mozilla.org/?product=firefox-pkg-latest-ssl&os=osx"