I don't want this to be a pissing contest, my statements are based on experience.
1. Unless it is a tenant, you can remove ANYONE from the property using REASONABLE force, rules are the same as if it was your own home. If they refuse to leave, ban them for a period of time ( 6months, a year etc) and inform them that if they come back, they will be arrested for trespass. I have found this a very useful tool. If you do arrest someone then you MUST call local LEO for pick up. you do have to file with your local JP yourself as the TPA is a civil charge and not Criminal code. If it is a potentially violent person then call LEO and let them play with the trespasser.
2. I am a dog owner. Have had a stubborn meter reader learn the hard way that that the yard is the dogs turf. What I am trying to say is that you keep your dog at your side and not let your dog approach cranky landowner. the landowner could justify shooting the animal. If you are attacked by a landowner and your dog defends you that changes things (and I hope your dog will take a nice big chunk out of the twit). Unfortunately I believe companion animals are still considered property in this country, please correct me if that is incorrect.
3. This applies across the country when laws and statutes conflict: provincial overrules civic, federal overrules provincial.
4. Another tidbit for you, out in public a citizen can arrest for an indictable offense, on private property he is in control of he can arrest for any criminal code offense. Also useful for those really stubborn trespassers.