It is perfectly legal. Hasbro has to place warnings on there guns so you can't sue them if you injure yourself.
No, if the person who owns the game allows it.
heck yea
No it is not illegal as long as you do not try to make any money from it.
Not technically illegal, however it is in breach of their 'Terms of Use', definitely ill-advised. They can, and will, ban your account and IP address. If you are gonna mod, do it offline only and...