There is definitely some confusion as to the capabilities of Starkiller. Since the Hosnian system isn’t destroyed early in the film, we aren’t shown that it can destroy something many systems away, and the first time we are made aware of this is apparently during Hux’s speech.

When we were watching this edit, we had a discussion about whether the Starkiller had any sort of propulsion system like the Death Star. Since I am familiar with the Corellian system in EU, I thought it was plausible that the Starkiller would be able to trundle up to any old star and use it as fuel for its hyperspace laser weapon, but this seemed absurd to certain other people. I don’t know how to deal with this problem, but I’ll keep thinking about it. 😃