Ontario's residential tenancies act stops landlords from restricting pets (http://www.e-laws.gov.on.ca/html/statutes/english/elaws_statutes_06r17_e.htm#BK15) and in my 3 rental apartments in Toronto I have not had trouble having cats. My current building explicitly had a "no pets" clause in the agreement, but at least 1/3 of the tenants have dogs or cats.
I lived there for a year and a half without a car. I lived south of the university nearby and walked mostly. The buses are pretty good. The city is pretty flat except the river valley, but there are several bridges. Hope this helps.
Back when I lived there, I lived up near 109th St and 76th Avenue. It was a bit of a trek walking to campus in the mornings but there was a bus that I didn't use. Most of my friends lived closer to Whyte Ave or in apartments closer to campus. It is nice to be able to walk (even in the winter if you dress right).