Can gas company determine that the gas was shut off at the meter (without sending to inspect)?
Most new appliances do not have pilot lights so if they are not being used there is no gas usage. Shutting the main off even during the time the meter is being read won't trigger an inspection. In Earthquake prone areas some home owners have a wrench attached to the pipe so if there is a concern about leaks the main can be quickly turned off. I have never heard of any problems from turning the main off.