I can't read everything and my time is at a premium lately but I thought I would like to throw in a few points.
Kylo Ren - Not only is Kylo wounded in his fight with Rey, but remember that he is very emotional and not in good control of himself. He stopped a bolt from a blaster without effort for an extended period of time at the beginning of the movie, but then has difficulties and even loses a fight later. This isn't a problem with the movie, this is consistent for the character. When surrounded by storm troopers, confident, and in control he has great power, but when suffering doubt, fear, or things aren't going his way then he loses the focus the force requires.
Rey - I hear so much complaining about Rey not having been trained. This couldn't be further from the truth! There is no better training than being placed in life threatening situations where you must act or die. Especially with latent force powers. Luke was a spoiled farm kid who started learning about the force without having been placed in any real one-on-one life threatening situations. Rey, on the other hand, already having fight training must fight or die. Fear, adrenaline, applying great effort would all legitimately bring forward her powers. She flies the Falcon, but remember she knows ships - HAS flown in the atmosphere (She says so when she says she's never flown in space), she struggled at first, and then had help from the force. And as someone already mentioned - in her battles with Ren, he is giving her the most direct intense training you can get. He gets in her mind and she is scared to death (great acting by the way) and struggles to resist and learns to resist and invade his mind. He taught her. After this encounter with Kylo she can, after several attempts, manipulate a stormtrooper. This same principle applies to the lightsaber battle. Where she didn't fight particularly well, btw. She learns from him while he is wounded, lacking concentration, and suffering doubt.
All makes sense to me. Of course, I've seen it 6 times now. But since it is episode 7 I will just have to see it once more. At least.