Contact your local police for current information.
You need to tell us more about the "gun license" and for what area. There are many different gun licenses.
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?
No
In the US, the BATFE issues licenses for gun dealers.
Yes because it is technically a gun
In US - no. In UK - yes. In Australia - yes.
10 maybe
Contact your local law enforcement officials.
Australia requires you to have a category "A" firearm license to own a BB gun
Nope but you'd might want to check this out. It seems the NSW Police half-assed it when they tried to build a gun themselves.
YES! or you could harm something or someone
In New South Wales (NSW), individuals who are at least 18 years old, meet the necessary requirements, pass a firearms safety training course, and have a genuine reason for needing a firearm (such as sport shooting, hunting, or occupational needs) can apply for a gun license. Applicants must also pass background checks and have a secure storage arrangement for their firearms.