Watched Ep. VII again this weekend. To go back to the Rey/Kylo duel debate: During the duel (and throughout the movie), I was more attuned to the argument that maybe Ren just wasn't that good a sabre fighter and not very strong in the force anyway, hence partially explaining why she was able to beat him. But I really don't think that was it. He handled his sabre just fine. And at various points in the duel when he was fighting either Fin or Rey, he did appear to just be toying with them and making them suffer a bit. At the end of the day, I think Rey beating him just came down to the fact that the good guy needs to win the light sabre fight at the end of the movie, and JJ tried to make it a bit more plausible by having Kylo wounded so badly. No need to overthink it. It just is what it is, and if you aren't the kind of person that can suspend belief and just roll with it, then Star Wars probably isn't for you anyway, since there are plenty of other inconsistencies you have to suspend belief for in order for the story to work anyway (and that is true of all the prior episodes, not just TFA).