Is this the way Hand Shakes mean?

I think so, but sometimes one person offers a shake and the other offers a fist bump, making the situation awkward. 

Then it became the “elbow bump.”

You should never rely on handshakes for anything. If someone offers a handshake, without either offering a draw, or saying they resign, regardless of whose turn it is, you need to clarify the situation.

You can make clear if it's a draw or resignation by the type of handshake. I mean, the resignation one is done firmly and the other more askingly. But yes, your turn determines it.

I don't know where you read that, but that sounds utterly bizarre. If your opponent starts thinking to accept the offer or not, then what? Do you continue to sit there with your hand extended, looking like a fool?

The correct way to offer a draw is this: you offer a draw (in words), then you make a move, then hit the clock. Now your opponent can think as much as he wants whether to take the draw or not, but at least it is his/her clock that is ticking.

No, it's not like that. If you want to resign it should be your turn and you have to turn off the clock and shake hands with your opponent to resign.And to offer a draw you don't turn off the clock and offer a handshake. I've read it on a chess.com blog.