And what makes the trees n plants grow while in between stars?
I didn’t even go to the effect on the planet of all this lurching and steering, but yes.
The steering system uses a planetary gear.
Thanks, this actually answers the question! 
Alas, although it makes speculative sense, it is just something I whipped out of the nether recesses of my digestive anatomy. It’s how an intelligent engineer would design the system; no one knows how it works in the movie!
They used the MILK* targeting system.
*Make It Look Kewl.
Honestly, it’s not a good movie. A lot of people has defended the total ripoff of *A New Hope * as some kind of palate cleanser after the prequels but it’s lazy and trying to play it safe. Doesn’t help that all the stolen elements are much lamer in TFA with Starkiller Base being the prime example.
The “villain” is such a weenie, you probably won’t even notice.
I want you to go to your room and THINK about what you did…
They fire it once a day.