1. yes you can. two days before the event.
2. stick to their requirement. no need to submit anything not on the list.
3. yes. just the stamps would be fine.
Asked to provide fingerprints twice. Got FP done by RCMP for over 2 weeks but the background status stayed in process. BTW, finished online interview recently and all seemed fine. The agent said it takes 4-5 months before ceremony.
I got interview invitation about a month after test. Need to provide passport scan and translation of stamps within like 2 business days to comply with the request.
Is there anyone whose test got cancelled in Mar 2020 and still not invited? It is frustrating and intolerable. I submitted a web form last week and got no replay either.