Icons can be assigned via Appearance -> Menus -> Click on a single menu item -> “Icon” property.
Please follow Theme Options -> General -> Appearance -> Layout -> Content width -> Enter the desired site width in pixels or percentages -> Save
You are able to create as many slideshows as you want and use them on any page or post.
Please follow Theme Options -> General -> Footer & Bottom Bar -> Footer -> Footer Layout -> Layout -> Enter the desired footer structure, f.e. 1/2+1/4+1/4 -> Save
There are 50px gaps between header and content area, content area and footer. You can add negative top and bottom margins (-50) in Visual Composer row setting to remove these gaps.