When I create an new page for a client and send it to him for review, I do the following to avoid it to be accidently published to live:

I set it to "Stage for Publish", publish it to the staging domain and set it back to "Save as Draft". Then I send the link to my client. As they frequently publish the Website, the page is regularly set back to draft and my clients are wondering why I send them a link to a 404 page.

So a third option would be great to only make it possible to publish it to the staging domain.