Hello SiWatts69:
Nice post! I live in the USA, so don't deal with 240v, but I too am VERY particular about my power on stage (and all other cabling for that matter)! I use 6x Furman P-1800 AR VOLTAGE REGULATOR / POWER CONDITIONERS (15 amps each, 11,160 watts total) http://www.furmansound.com/product.php?div=01&id=P-1800AR for everything (2 on stage for PA, 4 at FOH for mixer & racks). Expensive, but you've never heard anything as quiet or reliable (as long as the mains hold up).
I may be a little obsessive, but I have even replaced all of my removable power cables with expensive shielded power cables as these are the most prone to emitting 60 cycle hum.
ALL of my audio cables are star quad (2 twisted pair) for the balanced audio and single-twisted pair for any unbalanced cables, all with Neutrik gold XLR & 1/4" connectors. I do everything I can think of to reduce the possibility of induced noise. I'd bet I have one of the quietest live sound reinforcement rigs in this country!
I really appreciate the fact that you understand and care about these points seemingly as much as I do. In my 3 plus decades doing live sound, I have seen some of the SLOPPIEST cabling in the world! Whether it is by ignorance or they don't care I don't know, but I'm glad I'm not alone on this planet in trying to do things right!
4x L3Ms (mains), 4x L3Ss (mains), 8x L2Ms (6x stage monitors and 2x audience delays if needed), 32-Channel Mixer