While I have no solutions for the the To-Do List issue, I might suggest that you encourage your instructors to create Modules which hold the Assignments.
It's really a best practice for instructors to create Modules and direct students to them to access all of their course content. It's better to "hide" Assignments in the students' Course Navigation Bar so that students see all of the content in the Modules, particularly content-based Pages. In fact, I set up my Modules to have Requirements so that I can see whether the students are completing all of the items.
I find that students who rely on their To-Do Lists, the Calendar, or Grades to find their Assignments really miss out on a lot!