yes
Yes.
If you are an American citizen. Yes.
She sure can. There is no law that prohibits that. However, there may be some complications with changing his status if he decides not to return to his country. Google it. There are plenty similar questions/answers on this subject.
Yes, she can apply for a visa to bring her spouse to US
as if u are us citizen and try to marry someone from somwhere else i think it is ok. I'd say you're really lucky and must take the chance (only if she's from Tashkent LOL).
No not unless he become a legal U.S citizen. Which takes many years.
I presume from your question that the US woman is about to marry a man who is in the US on a Fiance visa. She can marry that person within 90 days of his entry into the US. Also the marriage should be a genuine one and not for the sake of getting a green card. If it is a fake arrangement, then the fiance may be deported back and the US citizen may face legal problems.
The first woman president of Costa Rica was Laura Chinchilla.
you take a test and do follow castros rules and do not sneak out any Cubans
My guess is that the question is not really if a tourist can or can not marry a green card holder (of course she can), but whether there will be an immediate immigration benefit for her. Unfortunally, not.
Marriage for the purpose of obtaining entry into the US is fraud and against the law.
If you marry a British woman you could become a British citizen. There are certain requirements which must be met. One of those conditions is that you must live in Britain for three years before you apply.