Wow, I'm happy to have changed the discussion to something way more interesting than just "like/dislike" the movie!
I agree with the whole rule of 2 thing. When Palpatine noticed that Ventress was getting a bit too strong, he asks for her to be taken care of, which makes it the rule of 2 in that case. But everybody is right that Kylo is a knight of Ren, whatever that is. JJ Abrams also mentionnend in an interview the Kylo is not a sith. That still leaves my question about Snoke. Where does he come from? Will we learn that Palpatine is still alive and trained him? Could he actually be Palpatine? Remember that we only saw him as an hologram, he could be anything/anyone, and any size for that matter!
As far as the combats... well Kylo is not done with training, far from it. He might not be that good at sword fight yet.
Finn is a stormtrooper. So he basically got an army training from birth. I do hope he knows how to fight even though they are very weak in the old movies...
Rey... they made a point to show us how good she was with that stick and how others feared her, the guy with BB-8 in is net. Its not far fetched that she got some martial art training of some sort and can handle herself quite well with a sword. Add to that the fact that the force is really strong with her and you got a very good fighter... So lets get the expansion out there to get the max level up a bit and some new levels/bosses!