Apart from that, the siphon works just like a
slinky, or if you were to link together a chain of paper clips and place the chain in a paper cup. Take up one end of the chain and lay it over the edge of the cup, pull the chain so that the free end hangs down below the cup - once you have enough weight hanging down, the force of gravity on the hanging chain will pull the rest of the paper clips out of the cup.
Not really. The slinky is a solid so each part can exert a force on the adjacent parts. Not so for a liquid. There is no (significant) tensile strength with which to "pull" more water through.
Gravity will tend to create a void at the highest point of the siphon tube. Ambient pressure (provided the lift is not too great) will push liquid uphill to fill this void.
Without ambient pressure the siphon tube will simply empty itself.
Yes gravity is the motive force but that is the 'no brainer' part of the equation (we already know that the liquid will pour out if we make a hole in the bottom of the container). The clever bit of the siphon is that the liquid starts its journey going uphill. A phenomenon that owes itself entirely to atmospheric pressure as the Oxford Dictionary so correctly states.