Hello! Regarding the keyboard navigation, are you by any chance playing the web version directly in your browser? If so, web browsers sometimes fail to register keyboard inputs for the game unless it is in fullscreen mode. Try making the game fullscreen (by pressing F11 in Windows) to see if that fixes the keyboard navigation and allows the 'V' key to work to turn on the screen reader.
If you are still having issues, I highly recommend downloading the Windows version, which we have thoroughly tested and should work perfectly with keyboard inputs. (We also have a Mac version available, though we haven't been able to fully test it yet!).
Let me know if this helps or if you need any more assistance!