A Newton is the force required to accelerate a mass of 1kg at 1m/s/s. Or at 1g, the force to hold up 98.1 grammes.
Yes, but your ignoring the outcome. A set of traditional scales can demonstrate: Put 1 Kg weight in one dish and the dish will continue downward until it is forced to stop. Add a 1 Kg weight into the other dish and this dish will fall forcing the first dish to rise until both stabilise level. Add another small weight to the second dish and it will fall again and the first dish will continue to rise but only by a predictable distance until a new balance between the two dishes is achieved.