It appears as if we have quite a few wonderful ideas!
In combining a few ideas, I think adding a text-to-speech component to the VR experience will help address issues with spelling may play to the strengths of students with dyslexia.
I'm also intrigued by the teaching methods used in the classroom. It appears as if physical movement provides a positive impact on memory. Perhaps the VR experience could capture and incorporate body movement into the lessons. For example, a word/sentence is highlighted and read aloud. However, for the user to advance to the next word/sentence they must draw circles around certain sounds or move in a certain way. Essentially, movement is required for advancement in the lesson.