I will answer according to the given order.
1.No,it is not.It is also available in Canada,New Zealand,Taiwan,Hong Kong and Brazil.(Source)
2.Yes,you can.You can use Pokebank in a country where it isn't available if you set the 3ds's country to one of the available countries for Pokebank. Source:Experience.(I live in a country where pokebank isn't available but I set the 3ds's country to USA and was able to use Pokebank.)
3.In my opinion,the reason they made Pokebank and Poke transporter was to make money.They also say that they did this to prevent people from using fake Pokemon,But we know that that objective failed.
4.I already sued them.So they put me in jail. Lol I'm joking to :P
Hope I helped!