Yootheme Page Builder does things differently than core. So not everything will work the same way.
Quick Index will make an index of the content that is passed to the plugin at the time of rendering. If you have the {index} tag inside a field that doesn't contain the content for the index, then it won't work. Neither will the Pro version.
Conditional Content should work with any content that is output in the html of your site.
But also here, if the {show}/{hide} tags are not in the same content as the closing tags, things will go haywire.
Thanks Peter, just testing my own CSS on native Joomla page. I need your plugin to work more than fancy element boxes, although I still love YooTheme and use it as my template. Just won't build some pages with their builder. Thanks!