This plugin will solve the how to fix the visual tab in Wordpress from breaking your script or html tags problem.
If you want to optimize your blog so that you can leverage the latest trends when your posts show up in the Google Search results you will want to use the Google Structured Data Testing tool frequently until you get your posts to show up the way you want them to. The Structured Data Testing [...]
Embedded YouTube video will block most popups unless you modify the YouTube Embed code to allow popup to override the YouTube video. You can try modifying the popup Z-index as well.