I have posts that are not showing up on the home page and on another page.
WP is set to 10 posts per page. There are 5 on the home page (there should be 6) and 1 on the Design page (there should be 2)
Also, is there a way to add additional images or type to the header?
I just cross checked it with on another installation, if the “Blog pages show at most” is set to 10 , it shows 10. There is no problem with the theme. Please see if there is any plugin which is causing the issue.
1. There is no specific size for the banner because its flexible, you can add whatever size you want, however if you want full size image, then it would be (Layout Width – 10), so if the layout is 1100px (look at the width under Apperance>Supernova Options>Styles) the width would be 1090px. I looked at your site, it would be 1090px
2. You would need to create a footer navigation watch my video.
By flexible I meant that, since it can be adjusted from ‘supernova options’ page, I did not mention the width of the banner, and its upto you weather you want banner or slider, but for slider you would need some coding skills, because you cannot just add the shortcode in header.