I like the idea of Rey being in Luke's academy for a time before Kylo destroyed it. Then Luke (or somebody - probably that old map piece guy at the very beginning) hid her in the junkyard - where she's "waiting" for someone to come back and get her. Of course, there's that scene towards the beginning where she is surprised that Luke isn't just a myth but that could simply be because she was really young in the academy and now she's starting to think she dreamed the whole thing.
Anyway, that would all be way better than her being Luke's daughter.
I also agree with a lot of the other comments about this movie borrowing too heavily from the original series. There's a difference between paying tribute to, and totally ripping off, the preceding storyline. Let's see:
1. Starts with a kid in the desert, strong in the force, who stumbles upon a droid holding secret information.
2. Hi, this is Kylo, the New Darth Vader, who was a Jedi pupil before turning to the dark side and destroying the Jedi Order, just like Old Darth Vader.
3. Hey, it just so happens the Millennium Falcon is here, which we again think is garbage!
4. Hey, the Millennium Falcon has smuggler's holds - let's hide there!
5. Hey, we need to do some emergency repairs on the Millennium Falcon!
6. Next stop, New Mos Eisley Cantina!
7. Jump to New Rebel Base, about to be destroyed by a New Death Star, so let's do a New Mission to Disable the Shields! Bring back Admiral Lobster for extra grins!
8. Let's mention sending Brienne down to the trash compactor in the New Death Star (but not actually show it, or give Brianne any face time whatsoever)!
9. Ok, real quick, let's insert a bridge scene with a big family connection reveal between the good guy and the bad guy (even though we spoiled that earlier). Plus, Harrison Ford has only agreed to a one movie deal.
10. Ok - now let's blow up The New Death Star with a New Trench Run!
Bonus: Next up Kylo goes to Dagobah to complete his training (with a guy who'll actually be small like Yoda), only it will totally be different because he's training to be a Sith!
So I'm sure it was a lot of fun for most fans of the Star Wars franchise - I liked it - but it's just not a very filling dish.