I've addressed most of these concerns in the last deployment I just did. The lack of notification on signup was a caching problem. After signing up for (enrol

I've addressed most of these concerns in the last deployment I just did. The lack of notification on signup was a caching problem. After signing up for (enrolling in) a course you should be taken to that course's landing page. A navigation section gets added to the sidebar when in a course that lists out that course's sections (assuming it has any). At that point, the norm would be to simply progress through the course's sections in a linear fashion but that is not enforced so you can skip around if you want/need. I guess I need to somehow make it more obvious what you do when you are in a course.