I am also a Torontonian, going to the lunch at Dynasty, and hope to meet you there. If you have food poisoning, consider seeing a doctor. I keep a prescription (Zithromax in case of bacterial infection) for emergency use in such situations (I've been traveling to Asia and Africa for other kind of professional work).
Back to the main subject- when you are traveling along the QEW you reach a place called Burlington Ontario where there is a steel mill. Depending on the time of day and the direction of the lighting, there can be dramatic industrial shots of smoke and smoke stacks against very stark backgrounds. You would need to get off the QEW, use a telephoto from the service road, or drive closer to the place. I haven't done this yet myself, but I intend to one of these days - at about 6AM when it is most dramatic.
In Toronto, if your into photographing veggies and street scenes, the streets that have open-air Chinese vegetable markets are colourful and photogenic. This would be blocks of Dundas, Spadina and Gerrard. Day and night. The Dundas/Spadina area is also where Kensington market is located and as others have said, there could be some neat photo ops there too.
Some of the major downtown glass boxes, depending on the time of day and weather, have interesting reflections and lighting because of their non-neutral tints. This subject may be a bit hackneyed, but who knows, there is always a different angle - worth watching for if you have camera in hand.
Shopping photogear in Toronto isn't that great an idea - others haven't mentioned yet - I'm surprised - apart from the higher prices, we also have higher sales taxes. You pay a federal "Goods and Service" Tax of 7% plus Provincial sales tax of 8%. I think you can claim it all back at the border, but you need paperwork and it is a hassle.
Hope you make here in good health.