In a confined space the calculations are really complicated, but after a while you would expect the virus to be roughly evenly distributed around the space, and so 2 metre or 1 metres does not really make a difference. Until the uniform distribution is reached, it will be some blend of the two situations.
No, after a while you would expect it to have settled to the floor (or other surfaces). The one/two metre zone is to allow the 'droplets' to sink below face level. The virus does not get a uniform distribution in the air. (as I have understood the science presented so far). This is why there is a greater risk standing face to face, rather than behind or to the side of someone.