May be for popularity Go game OGS needs a guest games like as chess server lichess.org.
Each guest can start game with friend, and get short URL. Second guest will can use this URL for playing with first guest.
Yes, it is.
Please see this feature on lichess.org “Play with friend”. No registration. Only click “Play”, gettin’ URL and tell its to your friend. This is most simple way to play.
I think it is a very useful feature for OGS too. With it OGS will be more simple for use.