I\'m using this CSS-only strategy for responsive background images and responsive background image and contained content ... an example of the type of setup I\'m using for b
It looks like you could simplify your HTML/CSS and that might resolve your problem.
Why not just add your background-image stuff to and then remove all those extra tags. Down forget to set your viewport meta tag. i always start with this and then change it as needed.
https://developer.apple.com/library/ios/DOCUMENTATION/AppleApplications/Reference/SafariWebContent/UsingtheViewport/UsingtheViewport.html