Cables routes: As you can see from the WIKI link above, cables must be run vertically or horizontally, so they cannot run outside those zones, so you need to eliminate those L shaped diversions!
Circuit. Need to know if the circuit/socket you are running from is a ring final or a radial. You cannot do as you have described with ONE cable if it is a ring final. You could if it is a radial. So, need answers to the questions above.,