I just called Canadian and asked them whether I can do this...they said perfectly fine. The only thing is to do it in two tickets and make it look like there is a Sat. night stay.
So it would be:

Ticket 1:
YYZ - YVR (Connect through YYC)
YVR - YYZ (Connect through YYC)

Ticket 2:
YVR - YOW (Connect through YYZ)
YOW - YVR (Connect through YYZ)

The reason for me making connections instead of direct flight is because short flight like YYZ - YOW is only < 250 points in reality but they will give you the minimum 500 points. which gives me a total of 2585 when in fact it is only around 2200.

One interesting thing is before I hang up, the agent "voluntary" said to me, you can even return to Toronto if you want, just do it in two seperate ticket.

I asked her to explain what exactly is "back to back", she hesitated and couldn't answer. She diverted the topic by sayinhg what I am doing is perfectly fine then moves on to ask whether I need to book it.

Regards,
Empress