Edit: I removed the embed YT video question. I have it working now.
Is it possible if you're working on a story but not done with it to Save as a draft, where it doesn't get published? Closest thing I could find would be to Archive it yesterday, and then check Never Archive when you're ready to publish. Is that the best approach?
1. If it's a regular thing, under Options/Access Levels, for the various accounts, set this item: Are posts made by this access level automatically approved?
to "No". This means that you'd have to click "Approve" on each article as it's submitted.
2. If it's an occasional thing, and you don't want to do this for every article, you can set the Date Posted on the article wa-a-ay in the future. The article won't show up until that date. When you're done editing, change the Date Posted to "today", and the article is posted.
#2 is also a great way to stagger several articles, automatically posting them as the date arrives, should you have a need for this.