I watched it again and really enjoyed it even more the second go around. I really have no qualms about anything the movie did. Sure I have some questions, but I also have theories that answers those questions. Makes me want to see the future movies even more. Therefore, JJ, mission complete.
The more I think about Rey, she definitely has to be either Luke's daughter (too obvious?) or someone he adopted and trained personally (she was still very young when she got dropped off at Jakku). She's definitely NOT Kylo's twin sister. The lightsaber vision could have been Rey's but I believe it to be Luke's. My smoking gun for Rey being with Luke is that when Kylo is interrogating her, he mentions that she dreams of an ocean and an island, which is clearly where the movie ends.
Last theory (don't know if this was mentioned): all of the EU stuff is not canon, but the movies are. Mara Jade is in RotJ thanks to George's bastardizing of those films. So a Luke + Mara could very well have happened and produced a Rey.







