Yes! that FedEx hill is a nice place and I once went there to collect my packet which incidentally was none other than my AC
ticket. There was one FedEx B727 packet right across the fence. Not sure if it is the best place to spot.
There aren't any international flight worth the name, but heard Ethiopian flies there due to their expat population. Not aware of any spotting locations, and unwilling to risk on my own. As for Wendy's parking lot, I made myself double sure from Kaz(AirbusfanYYZ) before I tried my luck. Won't really mind if cops ask couple of relevant question.
If you're interested in some general YOW
photos, feel free to see my online album, the link is in my profile page.