I agree with my colleagues. it is best to consult an immigration attorney. Generally speaking it would be easier for her to apply for green card after your civil marriage ceremony and for you to wait for the wedding in Mexico.
I agree with my colleagues. It is best to consult your school's office about possible OPT violations. As long as your girlfriend is a US citizen you should be able to apply for a green card after marriage. It is always best to consult an immigration attorney.
I agree with my colleagues. If you are dishonest on your application it can cause you problems. An attorney would have to look at the language of the statute but generally disorderly conduct is not CIMT.
You should consult a criminal defense attorney and an immigration attorney. If you have only been charged there may be the chance to reduce the charge. a felony involving larceny can hurt your chances of obtaining employment in the US.