I'm not entirely clear here about what it is that you can't do specifically. I am presuming that you have already gone to the YouTube site for the video you wish to embed and snagged the required embedding URL. I prefer this method to the new functionality that allows you to search for a YouTube video by title as this way you absolutely know that you've snagged the video you intend before you even start.
Is this the Microsoft Support Page you've read (and it covers this for PowerPoint 2010, 2013, & 2016)?:
I have Office 2010, but the first two steps are the same and they've changed the last two only slightly
I can't really speak to the controls within the PowerPoint presentation that are the result of the YouTube video being embedded at all. It appears just as it does on the YouTube page, so if you're familiar with the controls you'd use while browsing YouTube on the web those would likely work.
When you're in PowerPoint in design mode I can delete a video just by getting the video box selected and hitting CTRL+X to cut it.
Presenting the willfully ignorant with facts is the very definition of casting pearls before swine.