JM doc where are you from if you do not mind asking??
I am originally from South Korea and I am graduating from Osteopathic medical school and will be doing Allopathic Residency. Fortunately when I applied to DO school, I had a green card. and the school kinda pushed me to become US citizen. I knew guy from Indonesia who did undergrad and High school in the US. I did his favor by asking one of admission officer at school at TouroCOM-NY(school I will be graduating). and He said they do accept international applicant. But I have not seen any enrollment of international applicant to my school.
In order to enroll in Med school in the US, you have to show that you are financially reliable to pay school out of your pocket because you will not be eligible for loans and financial aids. Also If you have military requirement back in your country, you need to show that military requirement will not hinder your education. So what I will do is Whenever you send secondary applications, include those documents.
Now, let's talk about residency issue. If you are looking for surgery residency in the US, you will face tough situation. This year, 80 percent of allopathic General surgery programs were filled by US allopathic medical grads according to NRMP. Let's say you are DO, and if you want to apply MD gen surgery residency, you need to be perfect in every aspect of your application. Many Osteopathic students apply Osteopathic Gen surgery programs. Unfortunately, they do not sponsor visas. I am not saying it is impossible, but you need to work harder.
For you, you will have better chance in ACGME(allopathic residency) because they sponsor visas. I know one korean DO without greencard, he matched into ACGME psych residency.
I honestly think MCAT absolutely needs to be way more than 30. And Also, when you do interview, you absolutely need to say that you want to practice in the USA PERIOD. D.O. is a very american brand. let;s say you become resident doctor in the USA, your salary will be paid by medicaid(am I right??). so why would the USA want to pay you if you are not going to practice in the US. Also show that you have overcome difficulties as being international and you are willing to accept challenges.