Well, you provide a service to both your home state and country. Members of the National Guard are eligible for state and federal benefits. If you're new to an area, it's also a good way to help you find a job (speaking from personal experience here).
No.
no
No, you cannot.
A loan default wouldn't disqualify you from joining the National Guard.
Not FOR joining the National Guard or Guard obligations, but that does not mean they can't fire you for other reasons.
Depends on the specifics of your crime. You need to speak to a National Guard recruiter for a definitive answer on this.
Yes
Yes.
First, there is no Air Force National Guard. It is called the Air National Guard. The military does not train anyone to become a doctor. You would go to med. school yourself and upon completion of the course, join the Air Guard as a physician.
Depends on the type and for what condition.
It is usually not a bad idea.
yes