Crab
Having had a reasonable insight and lent him a hand all he is doing is taking best practice from loads of different industries and putting them together with an eye to making the machine as light, slippery and practicable as one can get.
He spent ages going through and looking at the design of a 500 main rotor head as it is relatively simple with a strap pack enormously strong as has been proved over 50 years. Has decided, having seen the 342's fenestron to go down that avenue as it makes the aircraft quicker ). As for the body shell look what Bruno has done with the Cabri, he is passionate about making the aircraft as clean as possible to reduce drag and increase the speed as this obviously reduces the need to carry so much fuel and hence reduces power required.
Will he get there ? having seen behind the scenes and a few long chats with him i think he will. Yes there will be some problems, but he has taken the best part of 400 orders, bear in mind Airbus sold just over 500 EC120's ( rubbish machine ) in 25 years !!!