The Octopus system works very nice. It uses one-way valves going to the struts so if your L.E. blows, your struts are still inflated. If your strut blows, you lose just that strut.
Wrong....if your strut goes on the Naish, then it will keep drawing air from the main tube because you have no way to stop it whereas on the Slingy you use the white clips to crimp off the hose.
If its a slow leak it doesn't matter much as there is so much more air in the LE.
Fast leak, well. I've never seen a fast leak in a strut that hasn't been caused by massive kite failure, eg it can't fly with the LE inflated anyway. So its not really a problem.