I was right to concerned about the wiring loom. That's what most of my time has been spent over the last few months.
Here's a few time lapse pics of the dash prep.
And the fuse panel.
But I've finally got it all working. Plugged in the OBD2 scanner and voila - errors codes as expected (for things I don't have connected!) when I get the ecu reprogrammed that'll get fixed.
It did give me a warning that my fly-by-wire accelerator wiring was wrong, and I checked it and sure enough I'd got the bottom row of wires back to front. Duh!
Once fixed, the scanner shows the accel position nicely! Graph goes up and down with pedal pressure.
Now all I need are my headers and I'll be able to get this baby fired up!