Yes, if you have a US ID and cross the border by car or foot, you will be OK.
No.
No. You need an ID or birth certificate in case you cross the border by land, or a passport in case you take a flight into Mexico.
No. Going beyond border cities such as Tijuana, Mexicali or Juarez (the later is highly unadvised to visit), you will need a passport.
Canada requires a valid passport to enter the country. In the past one could use a driving license or other ID, but today only passports are acceptable.
Now Canadians and Americans need passports when visiting each other.
You need an American ID, birth certificate or US passport. Note you don't need anything to cross into Mexico; however you will need any one of these documents to return to the United States.
If you have an ID and birth certificate, you shouldn't have any problem re-entering the US.
Yes, the three of you will need a passport.
No you cannot you must have a passport/id
The 42nd parallel borders CA/OR and NE/ID source: Wikipedia Your source needs a new source!
There are many ways one can get a California idea. One can get a California ID by being a citizen of the state of California and visiting a DMV location in California.
No. You cannot use a US birth certificate to cross the US/Mexican border in either direction. US citizens may use a passport (booklet mandatory for air travel), US passport card, "enhanced" drivers license or "enhanced" non-drivers ID.