You would be able to make your own gamer tag without any problems. Just make sure that you are not getting a banned console, because if you get a banned console, then you will not be able to use the gamer tag.
Yes you can create a new account but if you wanted to get rid of every bit of data the previous owner had just go to settings and restore to factory settings but this will erase any updates the previous owner had.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.