I’m wondering if it’s possible to do this, and if it is, it someone would be kind enough to point me to the documentation.
The idea is basically having an init script that runs when I start XFCE and it launches specific applications on specific desktops. For example, I log in and automatically Firefox starts on desktop 1, a terminal starts on desktop 3, and thunderbird starts on desktop 4.
If I were you I would probably write that script with all the things you want to do - which you can work on, edit, add to over time, and have that autostarted by whatever method you choose.