Feedbacks to Coursera support. The list is under issues tab (click!).
As Coursera doesn't have any issue tracker, I've decided to store the issues I'm reporting somewhere. This is the place I've chosen.
All opened issues haven't been solved by Coursera still.
Labels such as bug or enhancement shows the type of the issue. Take a look at wontfix labels: Coursera says they won't make these requested changes.
Feel free to vote for existing issues or create new ones (if you create a new one, don't forget to contact Coursera support via partner-support@coursera.org and to specify the date of the contact in the issue title).