Yes because it is technically a gun
No,
In US - no. In UK - yes. In Australia - yes.
10 maybe
There is no such thing as a gun license in the US. There are concealed carry permits/licenses and dealers licenses.
It depends on what you mean by license, and where you are located. If you mean a permit to carry a gun, in most U.S. states, the minimum age is 21.
Contact your local law enforcement officials.
Australia requires you to have a category "A" firearm license to own a BB gun
To get a gun license you would need to go into a gun store in the town you live in and ask for the information you need.
Contact your local police.
YES! or you could harm something or someone
No ... but their may be an age requirement.