Hi there, if you’re setting a static width in px to make it full width then you probably will have issues as it won’t resize responsively.

You can either use @media css queries to resize the image for each device, eg: ipad, iphone etc, so you’re setting a specific size for each. More information on @media queries can be found here – http://css-tricks.com/css-media-queries/

Or if you want something custom built via one of the developers, which will basically rewrite the section so its full width and fully responsive then it would be best to go directly to the theme customizers team to see if they could built a replacement slider for you, rather than hacking the css to break the section out of the main container box.