1. Depends, if you were born in Canada, then yes.
2. If your were naturalized, and the children were born after you became a citizen, then yes.
3. If you received your citizenship through descent (parent was Canadian, you were born outside Canada) then children born prior to April 2009 would be eligible.
4. Use the calculator. http://www.cic.gc.ca/english/citizenship/rules/index.asp
