Not unless you renounce your Canadian citizenship voluntarily.
If the stepfather has legal paper for custody, then the children under 18 are eligible for Canadian citizenship.
No. He is a US citizen (born in California).
Is the Canadian citizen also an American citizen or holds citizenship. if so then yes if not then. Technically no. This is because neither party holds a current American citizenship. If the Illegal alien was to marry upon Canadian territory then apply for american citizenship or Visa. But other wise legally no. However they should check.
No, you do not have to renounce Canadian citizenship to become a U.S. citizen. Canada allows dual citizenship, meaning you can hold citizenship in both countries simultaneously. However, when applying for U.S. citizenship, you must comply with U.S. laws and requirements, but renouncing Canadian citizenship is not a condition. Always check for any changes in immigration policies that may affect this status.
Unfortunately no.
The child would have dual citizenship; Canadian and American.
As long as you are living in Canada and have citizenship you qualify for health care.
Ted Cruz renounced his dual Canadian citizenship.
You have the right to enter Canada if you are a Canadian citizen. The passport should prove your identification, and the citizenship card should prove your citizenship - my guess is a strong yes.
Yes s/he can sponser a spouse. For the method please refer to: http://www.cic.gc.ca/english/information/applications/fc.asp As far as giving up citizenship: it is not required that the spouse give up citizenship. The US basically considers the spouse a US citizen and if they have citizenship in another country that is irrelevant to the US.
It is not possible to become a Canadian Citizen just by marrying a Canadian citizen. Citizenship cannot be acquired by marriage in any country.