hide the information under each article.

Unfortunately, not at the moment. Such functionality is not available in plugin. Though we will think about it and add this asap. Stay tuned!

#snippet-box {
      display: none;
}

Tested with Googles Structured Data Tool: https://developers.google.com/structured-data/testing-tool/

Sorry to be daft, but where does that code get inserted?
I’m using the visual editor, and I’ve tried adding a module that is raw html, as well as trying it in the header, and in both cases the snippet still appears. Am I missing something?

You have to add it to your style.css file.