These are what I think only:
1- Yes, you are eligible as a international student (if you meet all requirements)
2- You may submit the old one (it is better with the new one)
3- You may ask some IT guys from your country. They should know how to type it. If you can't, then use your name in your passport.
4- You may submit all T4, or ROE (Record of Employment), or all pay stubs (keep paystubs if IRCC need).
5- You don't have to wait for PCC, IRCC accepts the receipt.
To make sure, check more information here:
https://www.canada.ca/en/immigration-refugees-citizenship/services/application/application-forms-guides/guide-5069-temporary-resident-permanent-resident-pathway.html
https://www.canada.ca/en/immigration-refugees-citizenship/corporate/publications-manuals/operational-bulletins-manuals/permanent-residence/economic-classes/tr-pr-pathway/assessing.html#s5
I think the person may be eligible for worker stream. Graduate stream is for those who have graduated.
https://www.canada.ca/en/immigration-refugees-citizenship/corporate/mandate/policies-operational-instructions-agreements/public-policies/trpr-international-graduates.html
>Have completed, prior to the date on which the application for permanent residence is received and no earlier than January 2017
>Have been granted one of the following credentials, following the completion of a program study from an eligible institution as defined in a):
I think this rule was clarified in a live session by a lawyer. Or, "as an international student" in 1 is just saying "while you are an international student"?