Ok, now I understand, I thought you were giving up on the CSQ because you said 'you changed your mind'. Dont look at it that way, you sure not stupid, by doing this I believe that you are increasing your chance because even by going there to study etc...that route is not guaranteed either. The plan is simple (like many plans), but you know how life is..lots of bumps that we dont see. You just never know. It's just better to have a plan...and a backup plan, and this is just it.
I believe the study must be 2 years (not 1), just check to make sure. Also dont forget that you have to inform immigration office about any changes, so when you move, you will have to give them your new address. So they will know where you are and your interview should be in canada then. For the explanation about choosing Toronto instead of Quebec, well there are so many excuses you could come up with depending on what you doing...example...you believe that the program you chose is best taught at that school, it's less expensive that in quebec, you have friends there that can help you, and could go on and on with things you could say, and that none could just go ahead and go agains you for that. best of all you can say that you wanted to have a good idea about canada in general and that you took the time (during break) to actually go to Quebec! ;-)
For these things it's all about being prepared and that what you say is logical, you dont even (and shouldn't) lie. I believe that when (if) you do apply for PR, you should cancel your application for CSQ because I think there would a conflict there. I dont think you can lose both, I think the more recent application would cancel the oldest one. However, the best answer for this would definitely come from an attorney though.