I don't think dogs are allowed in the Eaton Centre.... I feel like I would have brought Tesla in there by now if they were, but I could be wrong! I usually leave him out front with the bf when I need to go in there.
TTC is our only mode of transportation and it's been a great success
My experience (from what I've seen) is that if your pup is in your arms during peak times you'll be ok, but I wouldn't recommend it.... subways and streetcars are packed tighter than a can of sardines during those times. Ride during off-peak times for a more enjoyable experience.
If you'll be down by the harbourfront, I've found that all of the patios here will do their best to accommodate your party with a table by the railing so you can have your dog tied up beside you. Technically pups aren't allowed on the patios themselves, so we just get a spot close to the edge. Be aware of Jays/Raptors games because the patios get busy before/after them and they might not be able to accommodate.
Highly recommended coming down to the harbourfront - lots to do and all kinds of new sights and sounds!
Pawsway is definitely a great place to check out. On Queens Quay, The Wine Shop allows dogs and I've occasionally brought Tesla into the Beer Store here too.
We also spent/spend a lot of time around the fire and police station. There's a multi-use path along here where we practiced getting used to skateboards, cyclists, runners, children, other dogs running by etc.
If you're not coming this far south, there are lots and lots of stores downtown that are dog friendly! Our favourites (because they give us treats!) are Winners, HomeSense, Home Hardware, a vacuum store at Spadina/Adelaide (sorry I forgot the name), and almost all the clothes stores on Queen St. Also, there's a pub on Queen St. called the Black Bull with a patio that's dog friendly (meaning they can seat you near the edge where you dog is).
If I discover any more I'll let you know