Hi Mike,
in Canada there are a few federal regulatory agencies that regulate hobby rocketry and other airborne hobbies. When you are operating in the city, all the land is owned by someone that, if you are operating "by the book", you must gain permission from.
Mostly, though, common sense prevails. The police would appear pretty ornery if they walk into an obviously fun, safe, enjoyable situation and start arresting people for obscure (for the general public) reasons.
I was told by a fellow looking into legalities for local launches that even flying a kite within city limits would be violating airspace regulations due to airport proximity, but really, who cares?! Common sense prevails. Most MicroMaxx rockets won't out-do a good kite for altitude, and they certainly don't pack as much mass, occupy as much volume, or occupy the same airspace over as much time.
When I asked the local Fire Marshall about flying rockets within city limits, I was told that we would need someone present who is certified to handle fireworks and who has purchased a permit. Yet fireworks can be bought at the local Canadian Tire by any adult. Usually they are used in back yards and in city parks without permits or permission. That might give you some indication regarding how strictly regulations are enforced in your neighborhood, and what the Fire Marshall is up against.
Liability issues might taint what local admin types will tell you. But if you chat with local police and city admin types, you'll get an idea how stringent local restrictions are regarding itty-bitty MicroMaxx rockets. When they actually see them, you'll get some pretty lenient, jovial responses if common sense prevails.
Fire Marshalls bear the heavy responsibility for fire prevention within city limits, so expect them to be pretty hard-nosed regarding regulations. That's their job!
I'd recommend being aware of who's responsible for what goes on in the launch area. If you are on private property, liability sits on the land owner. On school property, local school boards are liable. On city property, parts of city administration are liable. When you are aware, then you have an idea of whose butts are on the line.
For much better information, check out the CAR website.
Dwayne Surdu-Miller SAROS #1