I don't know if they're still around, with the spring migration already begun, but I've had some luck with Common Redpolls at Ashbridges Bay Park. When I was last there in February, they were in a stand of connifers right beside the parking lot off of Lakeshore Blvd. on the Western end of the park, and across the road from Woodbine Park. There are some homemade feeders up in the trees, and there were quite a few birds hanging around there, including a flock of American Tree Sparrows, Cardinals, and Dark-eyed Juncos, in addition to the Common Redpolls.
As for owls, I've certainly heard them in the woods along the Scarborough Bluffs at night, so your idea of looking along the waterfront is probably a good place to start. The Leslie Street Spit and Tomy Thompson Park, which Brian's already suggested, is known as a bit of an owl hotspot for Toronto birders, but it's only open to the public on weekends. If you're here for the whole week though, that would be a good place to try.
Best of Luck!
