[Firebird]

2: I think will be difficult

3: will be difficult as well but possible

1: You are from Canada so you are eligible for a Working Holiday Visa, so here´s a kind of number 4
Finish High school, go to Japan on a Working Holiday Visa (must be 18-30years), do some job (like teaching english or anything), learn a bit more of the language, see the culture and make some friends, experience life in Japan and see if you really like it. Than you can still decide after a year how you want to continue. And if you really don´t like it or can´t find a job or whatever you can go home anytime.
It can be hard to find jobs other than teaching english, even with the Visa, but you are a native speaker so teaching will be not to hard to do. Be aware that you will have to save up some money to get started when choosing this version.