Proof of funds doesn't apply to family class.
The accounting forms can be downloaded here:
http://www.cbsa-asfc.gc.ca/E/pbg/cf/b4/http://www.cbsa-asfc.gc.ca/E/pbg/cf/b4a/Unless you provided a picture that is exactly the size and clarity they want, they will re-take your picture when you arrive.
You'll get your PR card about a month after you arrive.
Yes, you can apply for the SIN number right after you arrive. You'll be given the SIN number at the time you apply and you can begin working as soon as you have it. Your SIN card will arrive in the mail one to three weeks later.