It all depends on what you mean by "protect"
A jacket should keep you from feeling anything below 300 fps at all, and will allow you to only feel a slight sting for anything under 400 fps. 400-450 fps might start causing welts though.
It would be foolish to do so. Always protect your eyes.
An Airsoft gun
That answer will change depending on what state you live in. What won't change is that an airsoft gun is not protection and may get you shot or hurt badly by someone who doesn't take time to see your 'gun' is a toy.
A pump airsoft gun is a gun that has to be pumped every time before shooting. Ex. Airsoft shotgun
No
How to properly maintain your gun, gear, how to protect yourself (glasses, facemasks, etc)
No
It is an airsoft gun based of the PPSH-41 gun
You never need a license to have an Airsoft gun.
No
No, it is an airsoft gun.
NO