As I said yesterday, the big theme to me is "where do I belong?" All the major characters ask that question and find out the answer through the course of the movie. Rey knows she doesn't belong on Jakku, she thinks she belongs with her family who aren't coming back, but she finds out she really belongs in training with Luke. Finn should know where he belongs, even his name FN-2187 tells us, he belongs between FN-2186 and FN-2188. But he can't stay there, he's scared and bolts. Han, Luke, and Kylo Ren all question their place in the universe, which I think is why so much of the plot resembles the previous movies, it's giving us a baseline to compare the characters against. I think there's also this theme that's starting to emerge of things not being able to stay the same. Luke Skywalker tried to recreate the Jedi and failed. Now there are no Jedi or Sith, just the Knights of Ren. Han tries to keep up his old smuggling ways but it doesn't really work for him anymore. Maz Kanata's been around forever, she's like a universal constant in the galaxy but now her save haven has been destroyed. The First Order and Kylo Ren try to keep Vader and the Empire alive, but outside of the Starkiller Base, they're not the ultimate power in the universe but a roaming band of assholes. The Resistance tries to be the barrier between evil but it seems like they're an underpowered, under-appreciated militia group.