If you are allowed to work in Canada/Europe/USA you are allowed to instruct and be employed as a Pilot.
A FAA license does not automatically allow you to work in the US. Likewise a EASA License does not automatically allow you to work in Europe. The same is true for Canada and collectively most countries around the world.
Having a license from the country you want to work in "might" increase your chances very slightly to find an employer that is willing and able to employ you as well as sponsor your work permit but without significant experience lots of hours and/or very specific ratings the chances are very low.
Getting a foreign license makes sense for conversions, price and quality of training.