OK, another couple of epic crashes yesterday after calibrating the escs.
Went back to the Naza manual, videos and FAQs and noticed the order that the Naza guy hooked up his motors. Counter-clockwise from front right M1-M2-M3-M4.
And realised that I had mine hooked up M1-M3-M2-M4!!!!
Issue was that I was building from two sets of instructions. The crossfire 3d print assembly guide and the Naza setup guide and they had different motor configurations (KK setup is different?).
I assumed (isn't this always when stuff goes wrong) that all Motor numbering would be the same for all controllers. Not so it seems.
I flipped M2 and M3 cables and we're up

I'll post some vids of the successful flight.
Thanks for all help guys. Now I can mount the action cam and start playing with some of the advanced settings.