Nate,
Thanks for taking a look. I merged in you doc PR yesterday, thanks for that.
The notices that you saw might be caused by how I setup the 4.8 SQL seed database. The admin user is removed from it so that setup.php can create the admin user and password on first run. I don't see any issues with the notices but I will try to rerun the setup with a fresh database to see what the code in admin_actions.php is trying to do.
Please let me know if you see anything else interesting in your testing.
Thanks again,
Tom