Sid,
I think that you may be getting a little off track with your assumptions -
Nr & N2
60% is idle with twist grips on the red buttons.
This is actually close to min flow on the fuel schedule. At that N1 the resulting N2/NR is what you would end up with at the current pitch setting. i.e if only one engine was running it would be lower and if you pulled the collective up N2/NR would reduce further. N2 is not governed in any way.
75% is normal ground idle (twist grips in normal detent'd position)
True but as these engines are FADEC controlled - N2 IDLE in this position IS controlled by the FADEC.
97% is flight idle
Nominal depending on DA.
100% is flight idle with high Nr selected
103% is flight idle on application of collective
100% is flight above 55kts
103% is flight when reducing below 50kts