So by that logic, you could put the line anywhere up or down the crossbeam and the righting moment would be the same? Might be right, but I ain't buyin' it. Put the line at mid beam or 3/4 and it will be harder to right, so why wouldn't that change at the top also? You have a longer lever.
Not anywhere. All the way down the crossbeam won't work.
Assuming you can keep the body straight (using the harness for instance), the effect is exactly the same, as said. But the lower the attachment, the higher the rope tension, so you it will be harder actually. Not harder to right the boat but to stay straight.
