Re: 4 player teaching
I'd recommend learning the basics in 1v1s, after perhaps one or two 4-player games to teach the game mechanics (turn structure, arrows etc.). 4-player games have this intricate politics layer to determine the winner, which falls apart if player A can't see that player B is threatening to try to eliminate player C.
We talked about threat assessment last night; everyone at that table needs that skill for a 4-player game to make sense.
Also, don't forget the floating gems rule on the last turn of the game; it probably determines who wins.