1- you’ll find the db password in settings.ini
2- you can put the file anywhere, e.g. in the home folder
3- yes, the Agile product code + region
4- login via ssh, and do php agile.php
you’ll ultimately want this run daily via cron
5- you’ll need to create a new MYSQL feed in Emoncms. If that type isn’t available, check settings.ini
Some command line tips here to get you going.
@TrystanLea may have a neater solution