Something in the options block the “view in youtube” links in the interface too, I thought it would but just checked to confirm, so you can't note it for future viewing that way either.

I'd suggest the best way to manage this is to provide your own “view directly in youtube” link with the embedded video, perhaps underneath, so your users get the embedded video minimal cruft by default but get the option of the fuller features if they have a youtube account and want to use things like adding to playlists.