Yes, if he or she has the proper license to do so.
Consult your local police.
The state of Illinois does not issue carry permits, so it's illegal at any age to carry a gun in Illinois, assuming you mean out in public with a gun permit.
You need to define the term gun license. In most of the US there is no license to own a gun. Some states require a license to carry a gun. others to carry a gun concealed. There is also a license to make or sell guns. All are different and have different procedures.
Yes- that is the whole purpose of a concealed carry license.
In states that require them, it is a license to own (not to carry concealed) a gun.
It depends on several factors; Where you are located and exactly what you mean by "gun license." Do you mean a license to carry a gun? A license to purchase a gun? A license to build guns?
There is no such thing as a gun license in the US. There are concealed carry permits/licenses and dealers licenses.
You can apply but not only will you not get a license to carry, you will not be issued any firearms license.
Sorry- Illinois has the most restrictive concealed carry laws in the US. Other than occupations such as police officer or armed security officer, you will not get a permit.
Nope. Pellet guns are fairly safe to use.
If you are 21 and have no criminal record there is no requirement to have a carry license however you do need one is you wish to carry concealed.