1) how long does it take to get permission?

2) what is Advanced Parole in terms of traveling?

3) how many times can they enter/exit the US while waiting for Permanent Resident approval?

4) dumb question, it is needed for Canadian travel right?

1) can take up to 90 days to get AP

2) is like green-card it is permission to re-enter the country after trip abroad.

3) I have read that it is multi entry, just have a photo copy of it to give the officer at POE.

4) AP is needed and a visitors visa to Canada depends if a person from the foreign country is required to have a visitor's visa to visit Canada, I know that South Koreans do not require a visitors visa, as well as anyone possessing a US Green-card.

http://www.cic.gc.ca/english/visit/visas.asp

You will take both copies of your AP document with you when you leave the U.S. Upon re-entry into the U.S., you show the officer your AP documents, which they will stamp and they will also stamp your passport. You will be required to show either the stamped AP document or the stamp in your passport every time after that when you re-enter the U.S. from travel abroad. You can use it as many times as you want, as long as it is still valid.

You are still required to have the AP documents when returning to the U.S. from travel to Canada, just like travelling anywhere else. Once you have activated your K-1 visa, and have applied for AOS, you cannot leave the U.S. and then re-enter without either AP or the GC.