Assalam u alaikum. Yesterday i landed in Toronto. That was a great experience. everything was smooth and you need not to worry. all u need is your visa stamped passport, COPR, and the declaration card (which will be given to u by airline at the end of your flight). At Karachi airport you will need a photocopy of the passport and visa. You might be asked for the Original CNIC which i didnt had but the people were carrying it with them. However, the supervisor told me that its not required. Strange..... one staff was asking for that and the other one just said not required. In a nutshell i was allowed without any big trouble.
Last but not the least i once suggested at this forum to travel along with PIA, so i am stick to this after my traveling experience yesterday. Flight was smooth although took off 55 minutes late and the meal quality was average but still it was direct, smooth, well served and safe. Goodluck