Google Plus – Does Google+ Have Groups Similar to Facebook

This has been fixed recently. Go to your Circles, right click on the circle you want to throttle or mute, and select "Show stream from this circle". At the top of the stream you will notice a slider that lets you adjust how much you want to see from that stream, including all and nothing.

Although I didn't test it, I'm quite sure they do. If you add an e-mail address to your circles, that address would immediately be linked to that person's profile as soon as he signs up. Then just the same check happens when he tries to look at that post, he will thus be in your circles at that moment.

What I don't know is whether he will see your posts in his Stream if he logs in or whether he will only see posts made after the time he signs up.

I'd say, you probably got plenty of friends not on Google+ so plenty of possibilities to try it out, let us know!