I got my PR as a Single, but my status changes next month and didn't go for landing yet because I am going to my country next month. I have an open work permit till September 2018.
You need to be careful here.
If you get married BEFORE you land it is REQUIRED that you update your marital status with CIC. You will then have to send back the COPR (with status "single") as it is no longer valid if you are married. You'll add your spouse to your your existing application, and they will process them and you'll both be able to land as PRs together.
If you get married AFTER you land, you can sponsor your spouse for PR. The only thing is that you MUST physically remain inside Canada for the entire process. Be prepared to be separated from your spouse for the duration of your application IF they cannot get a visitor visa.
Whatever you do, DON'T get married and land with a status of "single" on your COPR. This is misrepresentation and you'll be barred from sponsoring your spouse at any point in the future. (Misrepresentation May also lead to an investigation to have your PR status revoked as well.)
As for your other questions, my wife got a new passport with her new married name so that the name in her passport matched her name in the CIC application. Maybe not absolutely necessary but we felt better about it.