Loved it! Could have used some more exposition with regards to the state of the universe. Was that Coruscant they blew up? If the Republic exists, why is there a resistance? I kind of get the idea that the Republic was unofficially supporting them but I was very confused about the existence of the First Order and the Resistance. The complaint from the prequels about too much politics was valid, but I feel like they went too far in the other direction and were afraid to explain anything.
Aside from that (minor) complaint, what a great movie. Looking forward to Episode 8 in summer 2017.
From what I have gathered via Wookiepedia, after Endor, the Rebel Alliance refounded itself as the New Republic. Thereafter the Galactic Civil War continued between the remains of the Empire and the New Republic, this eventually boiled down into a stalemate with the Empire stuck to a few outer-rim planet strongholds. At some unspecified point the New Republic entered into negotiations with the Imperial Remnant for peace, and one of the conditions is the mutual disarmament of both sides. Some old Rebel Alliance commanders see the now new, First Order, for what it is and wage a 'Resistance' to it (while the New Republic is neutral, it favours the Resistance).
I thought the planet destroyed was Coruscant at first, however apparently it is Hosnian Prime and its surrounding moons. The New Republic sought to decentralise the government and the Senate sits at various planets with are voted for on a rotational basis. It just so happens the Senate was sitting in Hosnian Prime at the time Starkiller Base was activated.
Not sure how much of this is
spot on mind, but yes, I thought it was great.