Whether or not it's a good idea narratively speaking to bring another superweapon into this, I do like that the Starkiller planet seems to be encased in some kind of energy field. Something that's bothered me since details about Starkiller started turning up is that if this thing is supposed to travel through interstellar space to get to new targets, the surface is going to be uninhabitably cold between systems, and then the whole planet's going to thaw out once you're back within a certain range of a star (not to mention that the whole idea behind the device is presumably to destroy the star it's orbiting, so it's going to be abruptly plunged into cold and darkness by design). All the parade grounds and airfields and stuff on the surface in the second teaser would be ludicrously impractical if the base didn't employ some means of climate control.

Of course, I guess we don't even know that it travels. It could stay in one spot and take out targets from a distance. Maybe it can fire an energy beam through hyperspace.