Just install this plug-in, speed up loading YouTube videos at your posts.
By converting embedded YouTube videos to thumbnail images, you can shorten the loading time.
There is a setting that can conditionally disable the plug-in. * The number of embedded videos is within the setting value. * Put inside some tag has “disablethum” class.
At Edit Post view, you can use QuickTag for div tag has “disablethum” class.