Yes
No. Being a military dependent does not allow you to break the law.
You do not. Obtaining or possessing an illegal federal ID is a crime. The only legal means of obtaining a military ID without serving in the military would be to become a military dependent.
Yes, a valid US Military ID card will get you on a flight.
State or federally issued ID, such as a drivers licence, state ID card, passport, military ID, military dependent ID, etc.
In addition to a driver's license or passport, you can use a state-issued ID card, military ID, permanent resident card, or trusted traveler card like Global Entry to fly.
26 if they are enrolled in college
It depends on the situation. Generally speaking, not unless she can no longer take care of herself. A common misconception is that if a military member supports someone, that person becomes a dependent. This is not true. The mother would have to be declared legally unable to care for herself and then the child would have to support her and file the correct paperwork. Even then, though, her ID would only entitle her to use of the exchange, commissary, fitness center, etc. It would not entitle her to TriCare. She could use the MTF (Military Treatment Facility) on a space-available basis, but MediCare and her insurance company would have to cover the costs.
Probably "Special Privileges."
means that the ID card is for a dependent of a service member i.e, Wife, Husband, Daughter, Son...
may i use state issued medicaid card as photo id to fly commercially in the usa
No, you have to use an airplane