The Attorney General is head of his office.
Attorney General
Attorney General
Attorney General
The United States Attorney General
Only if you are talking about a specific person. If you're writing "US Attorney General Eric Holder, Jr.," then it should be capitalized. If you're just referring to one of many positions of attorney general with no name attached, it should be lowercase--e.g.: "When I grow up, I want to be an attorney general."
Yes - any job title should be capitalized
Usually when you address somebody in a high government office you either call them "Sir" or "Mr (then the title of postition)". So if I were you, I'd put Mr. Attorney General.
The proper abbreviation title for an attorney is "Esq."
Adriel Brathwaite is the Attorney General for Barbados.
As of 2013, the Attorney General and Minister for Legal Affairs is Allyson Maynard Gibson.
Titabu Tabane is the Attorney General for Kiribati.
The title of the Cabinet members in Canada is Minister. There is the Minister of Justice Attorney General for Canada, Minister of Health, and Minister of industry, to name a few.