If you have a wife, a house, or investments in Canada under your name you are a resident for taxation purposes. That is the simple way to know if you need to file.
If you are not going to be owing taxes you are not required to file a tax return until you return to the country. If you do need to file there is a page within your form entitled “Declaration of World Income”, or something like that. You fill it out, it’s simple, with the amount you wish to declare that you made here. That’s it. You can declare that you made your basic exemption, that you were studying Chinese and be done with them.
There is no way they can trace your taxes paid, and money made in Taiwan. It’s not a country, remember? They have no diplomatic relations with Taiwan, and thus no treaties between taxation agencies.