I don't fly for ORNGE, but I flew out of YXL for a number of years on the PC-12/45 (I feel your pain

)
Here's some of the numbers (KIAS):
VMO - 236 (0.48 Mach)
VO - 158 (9921 lbs), 151 (9039 lbs)
VFE - 163 (15' Flap), 130 (40' Flap)
VLO - 177
VLE - 236
VS - 91
VSO - 64
VX - 110
VY - 120 (dropping 5 kts for every 5000' above 10,000')
VR - 79 (15' Flap), 73 (30' Flap)
VREF - 118 (0' Flap), 98 (15' Flap), 89 (30' Flap), 84 (40' Flap), 108 (15' Flap + Ice Mode)
VREF - Ice accretion 108, 134 if boots failed
Holding - 150, clean
I've never flown a PC12, but it seems to me it'd make sense to fly at a fairly high speed to the FAF, then slow?
Depends, on your company's profile I guess. The operator that I worked for, SOP for IMC was to slow to 150 KIAS for the procedure turn (if required), slow to 120 intercepting the inbound, and slowing to Vref+15 past the FAF. Low visibility circuit was to be done at 120 KIAS. VFR on the other hand was "go fast" to the FAF, slowing for 160, then "flap, gear, flap".
One more quick question: is it SOP for you not to cancel IFR in good weather (good VMC) with traffic behind you?
Comes down to SOP's and Company Policy again. I'd argue that airmanship should play a role in influencing your decision.
With that said, I'd like to think that most operator's have in their SOP's, a line that goes a little something like this:
"SOP's have been produced to maintain a basic standard of flying. They are also intended to facilitate a safe and efficient operation. Deviations from the SOP's may be necessary under certain circumstances; however, the procedures listed in the SOP shall not restrict the pilot's authority, nor their ultimate responsibility for the safe operation of a flight."
Have to ask yourself: Cancelling IFR on a VFR day, although it may be against your SOP, does it really detract from safety? Understand that when you fly IFR/IMC, you are in a system; a system designed to move planes efficiently. When you cancel IFR, you are now responsible for traffic and obstacle clearance. Is this increase in workload so much that it distracts?
Cheers!