The real question with Rai (Ray?) is ....... Is she lukes daughter. I've seen it go so far as "dude the movie hits you over the head with it the entire time". I don't think it really was a thing you just had to assume, but I think they left it open ended on purpose.
Originally leaving the theater I thought that the reason she was on Jakku was because Luke left her there and promised he would return, but not necessarily because he's her father, just that he was beginning to train her or something.
There's really nothing we know for sure though. The things we know are
1. She has a strong tie to Jakku and was told obviously to not leave it and is waiting for someone to return.
2. She has a crazy amount of ability over the force without ever being "trained" in it. To the point where she is doing shit that even the best Force users struggle with at first, and she makes it look easy.
3. Lukes lightsaber "calls" out to her, the one from Empire strikes back.
4. Kylo Ren seems to know about her being on the planet and seem's worried that Finn find's her in particular.
5. Her Uncanny knowledge of the Millenium Falcon.
That's just the stuff off the top of my head that I can remember after seeing the movie just once. I think the sign's do kind of point to her being luke's daughter, but they don't say it specifically. For all we know she could be Kylo Ren's twin that was seperated from him (another theory thrown around)
It's tough to say and when I watch it again I'll be looking for signs that point one way or another.
I was really hoping that Finn would be the one that was chosen and it was a mis-direct the entire time to think that Rai was really the one with the force power. Though it did kind of point that maybe he has something hidden deep down.
You could see the whole Finn replacing Han solo as Han thing throughout the the movie, and the scene where he dies was coming from MILES away; MILES. It's really tough because its hard to feel really upset about that scene like some people on the internet are saying they got, and how shocked they were.
It was so clear he was going to die that it was tough to feel bad about it, when you just kinda "knew" it was gonna happen. I'm not a Super Star wars nerd so maybe it hit them harder, but I didn't feel much during that scene.
I'm still worried about the series going forward once I heard there were 3 different directors for the movies; but I actually enjoyed this one which surprised me. The next movie will be the make or break of this "new" trilogy though; and I don't envy the task that the writers/director have in front of them.
At this point the next movie has to Live up to the Empire Strikes back, which seem's almost impossible when you think about what that movie did. It had the most depressing ending of any major blockbuster movie (maybe ever?), the bad guys won, and they revealed probably the biggest twist in Movie History.
Now you have to make a movie that tops that as the second in the trilogy, while ALSO not making it obvious what twist is coming while being just as dramatic.
Tough task ahead of them. Also i didn't like the new Yoda lady.