Issues Responsiveness (iPhone)

I’m enjoying your new theme and using the full array of options to design a good homepage. I want a full width look without white margins. I think I’m close to what I want it to look like on a desktop. Yet on the iphone it totally messes up: layerslider doesn’t fit the screen, headings too large, columns out of line,etc.).

Version that looks reasonably ok on desktop and iphone: http://www.waardevolleven.nl/alternatief

Version I like on desktop but looks ugly on iphone: http://waardevolleven.nl/alternatief/?page_id=16812

Do you have any tips on how to influence the reponsiveness????