Yeah I agree, the acting was good, the directing hmmm... well as you mentioned the plots and some of the details could have been more consistent. I guess we may find out in the next movie who Rey's parents are, at the mo it keeps us second guessing. Overall I enjoyed the movie, I'm a big Starwars fan.
Maybe she was born from the force like Anakin.
Much like in the bible with the Virgin Mary and Jesus, Anakin had no father so to speak. His mother's conception resulting from the actual force its self. Personally I would prefer it if she turns out to be Luke's daughter. I think that because Anakin was "special" it would be fitting that his descendants do actually bring balance to the force.
I like the fairy tale scifi nature of Starwars, I think this is what appeals to me so much. I hope that they keep that theme throughout any further films they make.