Great to hear that you have new things lined up. Congrats and wish you the best with those.
Font awesome should work fine with the theme. I have 500+ IcoMoon font icons loaded with the theme fontawesome should be no different. In fact, I started out with fontawesome initially for our themes but later moved to IcoMoon since they looked better at that time.
Header background can be set via the setting named “Background for Header Area” under the Backgrounds tab in the theme options panel.