No you have been mistaken, I am referring to another quest which I did but if you wanna know what you get after the three keys look at the spoiler below
Edit: You have to go to the island after getting the 3 keys sorry for not including that
Edit 2: All your questions will be answered within v2.0 (which may or may not be existing)
Except for that Zero question.
I can probably answer that, if you had heard that from the guy who trapped you in that van, he is the opposition to the Imbalance of the World
but since you haven't completed it and therefore did'nt beat the abnormally hard boss with the flippin full team of plat cards platinum shiny team and that other boss which obliterates your team, you won't get most of your questions answered till then.