The mechanism selection of the opponent

I apologize in advance for possible language mistakes in my post :)

I have two questions.
In what way is selected opponent in chess live?
When I create a new game, drawing is for me an opponent who has the same game settings as mine and he's create his new game in this same time as me?

And the second question:

If a player with a far higher ranking than me, join my game (click on my dot on the graph), I can leave the game, without breaking the rules of fair play?

Let me just give you a few resources that will explain the selection process.

http://www.chess.com/forum/view/livechess/new-logic-for-auto-pairing-and-seek-graph

and

https://support.chess.com/customer/en/portal/articles/1622811-how-are-seeks-matched-in-live-chess-

I didn't really answer your second question though.  Very few seeks actually make it to the graph these days.  Only custom games basically so I wouldn't worry about that happening.  And from the Fair Play Policy:

Do not Abort games to find preferred opponents: Restrict your challenges and/or filter the Seek graph instead!

Ok. Thanks baddogno!