No
In the fourth DLC at the end.
It should, it works fine for me and my friends.
Yes You can play Borderlands offline you can play with up to 4 people on split screen but if you have a ethernet cord you can play system link with two people
Yes but you have to wait some time before you can fight him again.
If you mean can you fight your friends, yes you can, you need to enter an Arena, there are several to find, once in the Arena you can 'duel' with your friends.
Yep, 2 player offline split screen is confirmed.
Assuming you have the 4th Borderlands DLC, the Interplanetary Ninja Claptrap is the final boss.
Im pretty sure u can only fight it on online mode like Loa Shun Long.
Borderlands traditions tend to be mixed. Please specify WHICH borderlands you are referring to.
they would fight alone
the creator of borderlands is Gearbox
Yes.