Maybe the Starkiller's power comes from the planet core or something.
Maybe it's a weird kind of core like Naboo's.
It's powered by red matter.
I always took the "planet's core" comment by Boss Nass to be referring to deep waters, not actually going through the planetary core.
But, that was just me. I cannot find any information, canon or non, that indicates the Gungan city's location in relationship to Theed.
Then he is more powerful than any of us could imagineWhat if Luke's already dead?
It will be interesting to see what path Luke has taken. I had an idea that Luke ends up saving Finn from Kylo and that might be his reveal. But, that is just my own theory.
Could be but i don't want a repeat of JJs first Star Trek when Kirk just happens to be ejected over the right planetoid to find Spock AND Scotty (one of the few gripes i have with that movie). There better be a damn good reason why Luke is suddenly appearing in the middle of the fight to save the new heroes ass.
Otherwise i'm very curious how Finn gets ahold of the lightsabre and if he can stand up to Kylo Ren (i don't think Stormtroopers get trained in sword fighting much less where he will get Jedi training if Luke is missing).
Unless the First Order stormtroopers receive some measure of sword training, similar to the original conception of them by McQuarrie.
I have no doubts that they will have a good reason for Luke to be where he is, and show up when he does. Regardless of Abrams' inclinations, I have a great deal of confidence in Kasdan to connect it all together.