There is such thing as an "Inactive National Guard." There is also the Inactive Reserves. National Guardsmen meet one weekend a month, and train two weeks a year. Often they are activated and deployed.
Inactive Reserves may or may not be activated, depending on the need of the service. Actually, there is such a thing as Inactive National Guard. You will need the National Guard Almanac for a more proper definition. I remeber reading about it some years ago. If you cannot complete your enlistment obligation, you can request it through your commander. This is usually done due to a hardship or serious illness. NGR 614-1
You don't enlist directly into the Individual Ready Reserve. When you enlist into the military, you commit to an eight year obligation. Let's say you do a four year active duty stint, then decide to ETS without going into a reserve component. You are then placed into the IRR for the remainder of your obligation, during which time, you may be recalled into service.
No.
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
Talk to your last units clerk and he/she will get the paperwork started.
It would be difficult. It is up to you to attend drills with your unit. You may request to be ING (inactive national guard) by notifying the unit and see if it will be granted.
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.