Update for readers: I contacted Udemy Support. They advised you have to contact the Instructor Support team instructorsupport@udemy.com to request cloning an existing course.
The response was quick - they cloned the course for me and now I can edit the bespoke/tailored parts easily.
On the other issue: I got into the Published Instructor Club automatically the following day, it looks like it just takes a couple of days for that to work through the system.
