What is the effect of claiming more hours of training/courses in Canada's Employment Insurance (EI) claim?

The number of hours is not in and of itself important. They just want to make sure that you are actually still available for work. If you are willing and able to drop the course, it should be fine.

I'm not positive about the unemployment laws in Ontario, but I do know that here in America, you can not file for unemployment if you were fired or quit. People go around in circles trying to figure out which of the two, fired or quit, would get the insurance, but neither will ~ in any scenario. Unemployment can be filed in the first case you mentioned ~ when you have a job, but they can't give you enough hours; seasonal jobs are notorious for that. Generally, unemployment will pay for up to forty hours weekly that you couldn't work, and one simply has to file the claim and submit the claim sheet every two weeks. They keep an open claim for you as long as you have benefits coming. The rule is: if you and your employer agree that you are working for them but they can not give you enough hours (especially in the case of a lay off), then you are eligible for unemployment insurance. Don't quit and file unemployment; they will tell you "no".