Editor for teachers to create exam, exercises, and questions

I'm making a webapp for my local university, which allows teachers to create exams made up of open-ended/multiple-choice questions and JavaScript programming exercises, as well as group them by topic and a whole host of options to randomize the items in the exam, plus other settings.

I am not particularly experienced at making user interfaces, so I'd like some feedback as to whether the interface looks nice and user-friendly, and what could be done to improve it. My main concern is the interface could get cluttered up and become hard to navigate as more and more exercises are added to an exam.

Here are some screenshots of the app, followed by a brief video showing how it's navigated in a browser. I apologize for some parts in which language gets mixed up, that's for unrelated reasons.

Here's the part where you add topics:

Here's a couple collapsed question editors:

Here's one of the most important parts: the fully expanded question editor

Here's the coding exercise editor:

Here's a view of a list of a few topics, some of them with their optional text editor opened: as you can see, it can get cluttered:

Video

Lemme know if there are any more details I could add.

One idea I've had is to add an index to the beginning of the editor, briefly showing the topics and their questions/exercises, with links to jump to them. An issue I see with the current layout is there isn't any "logical" grouping, i.e. exercises and questions appear in the order they were created and not grouped by topic or any of that.