Hello,
1) Provide us with WP Dashboard access to your site because I don’t see the mentioned issue with the mentioned heading. Maybe that was some custom CSS or browser cache.
2) Use the paddings to limit the width of the banner content http://prntscr.com/s6sgk5
3) Either add padding/margin for both right and left or use WPBakery Responsive module https://gyazo.com/f33a5fb2007578369a433176cad8d47d and set padding 0 for the mobile device http://prntscr.com/s6sldh
Regards
