Good question. First off, do not go to an Army recruiting station. That's just for active and army reserve. You need to go to a local state armory and see a recruiter there. If you can't find one, call 1800GOGUARD or look up army or air national guard, they have various websites to help you locate the closest armory to inquire. All states have their own NG website. Good luck.
No.
No, you cannot.
no
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