StarKiller base is a bigger, and 'deadlier' version of the death star. It is a planet that is cold, snowy, and a weapon. I mean seriously, a cannon inside a planet? Maybe the dark side went a little to far. Or was it the dark side?
Luke SkyWalker's name was originally meant to be Luke STARKILLER. Here something maybe familiar? In the new movie, it was mentioned that Luke was a Jedi master, and he taught younglings (children). Luke could have made Starkiller base for the kids to train, and a weapon just incase another empire was created. Then, the 1st order took over, creating war, and fear (But not the kind that makes you try to kill your mentor and burn to death).