"Note: The results of your exam are only valid for 12 months. When you submit your application for permanent residence, the results of your exam must be valid for at least 6 months. If we approve your application, but you do not come to Canada as a permanent resident during those 12 months, you may need to have another exam. For this reason, it is a good idea to complete the exam as close as possible to the date you submit your online application."
http://www.cic.gc.ca/english/immigrate/skilled/apply-how.asp
I don't know if there's a link for the passport expiration problem, but it is common practice in most countries that they won't issue a visa beyond the passport's expiration date.
Hence the requirement of many countries to still have six months' validity on your passport even if you travel as a tourist.