yes you need RTPCR negative report only while entering canada.
you need to fill arrivecan in advance.
yes you can, just tell them this will be your address.
tell them a reasonable reason for your soft landing.
yes, i myself went by my personal 45 days old car which still has temporary US number.
make a list of belongings in advance which you will be moving in future. pictures and serial no of expensive stuff. car etc
Most important - Carry all original documents with you, approved i-797, I-94 etc.
Do not carry any fire arm, weed, dope or any illegal stuff

. My car did not get inspected neither at canada port nor at USA border crossing and they all were very polite and respectful.
But i saw how they were inspecting other peoples car.
Good luck my friend! Hope that helps.