Just now have time to think about some of the things in this thread. Like
@Ronoh I came out of the film not even questioning whether we were intended to believe Rey was Luke's daughter. I don't see how anyone could get anything else out of it.
I'm not saying there's some airtight case that that's what they actually
will do, but if they go another way I will see it as a pretty ridiculous dodge by JJ/Kasdan/etc. What are we to believe, that Han/Leia had a daughter and didn't know or that they gave up their daughter and it didn't occur to them that this chick who would be the same age and starts wilding out with the force might be their little girl? I don't think it's a plausible plot point and unless they handle it in some way I can't foresee, it will be weak. Although one really cool alternative would be if she were somehow Obi-Wan's granddaughter.
I actually think the questions that arise from the film that seem to be frustrating loose ends for other people - What's the deal with Snoke? What's the nature of the relationship between the Resistance and the Republic? Why was Rey left on Jakku? - are strengths in my eyes. I wouldn't want them to pack crazy amounts of exposition on those subjects into this movie and it would be weaker for it if they did. The movie is already on the cusp of being too long.
And remember that we didn't know shit about Luke/Leia/Vader's relationship in A New Hope. That stuff didn't come out until Empire, so why would we expect it to be so different here? The one thing I could say is that the end of A New Hope wasn't a cliffhanger in the way The Force Awakens was, but that's more about the fact that the original film wasn't assured a sequel. I would bet my life that if George Lucas had known he had at least two more movies in the pipeline, there'd have been some kind of serious tension at the end of A New Hope to be resolved in Empire.
As for Adam Driver as Kylo Ren, I was also underwhelmed when he took off the mask, but after a bit, I thought he/they made it work. Adam Driver, of whom I am not ordinarily a fan, is a peculiar actor with a peculiar style. I have to think they purposefully cast an awkward actor in this role to portray something about the character. Perhaps they want to get across that he is physically slight and by nature ineffectual (or perhaps is made this way due to his internal conflict) and has turned to the dark side in order to counteract what he sees as his weakness. I would expect his motivations will be more fleshed out in the next movie (or next two) and I wouldn't be surprised if this played some part.
But I knew about Adam Driver's role in advance, so it wasn't any kind of shock. Just like I think everyone on the planet predicted Han would die and so that scene didn't have anywhere near the weight it would have had if we had been caught unaware.