Query breaks the featured image, and changing page.

Site for reference: https://www.sinceresarcasm.net/

I recently tried using a query to stop certain posts being outside of their designated area (Bad Music Videos). This works, but it also causes two large problems.

The first problem is that the featured posts are on the main timeline, as well as the featured content slider, with the featured image. This is apparent on the above link.

The second is that when you change page, the URL changes, but the home page is loaded again.

I used the code

<?php
   if (is_home()) {
      query_posts("cat=-347");
   }
?>

on the index.PHP Twenty Fourteen, just underneath <div id="main-content" class="main-content">.

If any more info is needed, let me know.