Here here. The reason Luke and then Rey were so special and the focus of the movies is because they were above and beyond the normal force users, aka they were naturals. The force is magic, first and foremost so I have no problem with it. And let's not forget Lucas based the whole concept on the Japanese art of Kenpo which is, go figure, a type of sword fighting. If you are one with the force, it will guide your actions, Luke learned fast and so did Rey, so one can see lightsaber dueling to be the most easily tapped into.
And to me, the majority of the training was to try to teach potential Jedis how to not accidentally succumb to the dark side and much less about pure battle-prowess. That's why they wanted them young, not because they couldn't learn later, but because that is when it was easy to teach them right from wrong.
Let's not forget Rey was a badass with her staff on that rough planet for years, obviously using the force naturally during many a fight. Kylo getting hurt is believable to me, because it also means something that Kylo was just part of a huge gut wrenching scene that probably bordered on him thinking about suicide right afterwards anyway. He obviously was extremely conflicted about the whole thing.