You may want to check the following link out, if you are looking for MSC admission in Canada and you have poor CGPA (not too poor though) and if you are looking for 1 yr program.
http://internetworking.engineering.dal.ca/
Not a problem at all. You will get it if you study last two years in Canada (of course, as a transfer student, you won't be able to transfer more than 2 years of previous courses)
Official it is stamped and sealed by the institute. If you open the sealed envelope, it is longer official. So it is better to send notarized copy if you are not able to gather more than one copies of your documents (i dont know how it works in your country).
What would be the status after following:
Passport received at High Commission of Canada, ........., .........., Pin:.........., Tel: on dd/mm/yyyy and is under processing.
Why would you do Post-graduate diploma after Bachelor degree. you supposed to go for to to Canada for a higher Canada. Though it is a post-graduate, the 'diploma' is not a Master's. So you need to do some research about it as well.