I have fixed the bulk of the issues after realizing each gallery takes on the form of a post, so I edited the single-post.php file. The only issue I’m having above now is:

When I set the number of images to display in each gallery, it doesn’t work. It displays 7 on the first line and 1 on the next and then adds the others to a second page. I want at least 14 to appear on the first page before going to the next.