Hello Manuel,
We should disable the option “Use sample” in settings of ves pages builder extension to disable elements.css of ves base (because in the theme we dont use it).
About the padding issues you mean. The theme layout demo5 we are using layout full width. Your site are using layout “Boxed Desktop Large” you should change to “full width” in admin > venustheme > ves template panel > theme control panel > in layout settings tab.
 
http://demoleotheme.com/bigstore/index.php/?___store=demo5