Hi Nathan,
In addition to the articles that Yisrael sent you, there’s also this tutorial. I wrote it about hiding the Video Player but the principle of checking to see if a field in your collection is blank for a given item is the same.
Also, you don’t need to both collapse and hide an element. In fact, that might be part of your problem: collapsing elements means they don’t take up any room on you page. Hidden elements don’t appear on your page, but they still take up space.
Hope this helps.