I saw a reviewer make a comment about how, while the film really is a retread of A NEW HOPE, it was done in a way that would bring old STAR WARS fans who may have been disenfranchised with the prequels back into the fold. Their going back to old territory was a way of not so much erasing what had happened in those films, but to bring new life into the franchise. Less green screen and fake looking surroundings, no Gungans, no political and financial debates, just a fun film, which is my view on it. I still enjoy it. I have a feeling that, as this new trilogy goes on, we will see more original content and less returning to the well.
As for the First Order, I wish they had used the premise from the Legends novels, which was that the remnants of the Empire still had a hold on a few systems, and that they continued a fight with the New Republic.