206,
1. guessing, but at idle/idle, probably 3-4 gph, at 100%/idle probably 6-7 gph.
2 because , assuming you have maintained speed, and height, the torque /power requirement has remained the same:ie, you have increased the collective and adjusted the yaw pedal by a little bit, so the "guv`nr" says , i now need a bit more fuel to compensate.Works the other way as well.
3 Company OCM will say, unless State CAA override.