1. I think you’ve already added the parallax fix in your Custom CSS for mobile and I’m seeing your background okay. Are you still having an issue with this? If so, you might try adjusting the background position field on the page.
2. Not quite sure what you mean on this one. Can you provide an image?
3. In your functions.php file, try removing or commenting out this line:
Still not seeing the slide numbers in your images on any mobile devices. You might try refreshing your cache on your phone to see if that resolves the issue. If you’re still having it and you’re using the Metaslider plugin, you might want to try posting on their forum.