Sending a ship into hyperspace to attack other ships. Requiring ships to have fuel but allowing littler ships to escape from the slowest high speed chase since Oj and the bronco. 
Force ghosts being able to do anything in the physical world. Nevermind the fact that Yoda uses lightning (typically a sith ability), he's a Force ghost that can manipulate the real world! Wtf?
Luke regressing from all of his growth in the OT where he went from reluctant farm boy to galactic hero. He turned from galactic hero to cowardly, murderous old curmudgeon. All off screen mind you so we see nothing of how he changed. Just that he did. The only glimpse we get is that he tries to kill his nephew based on a feeling. Luke, the man who couldn't kill his father despite the emperor egging him on to give in to his hate, all of sudden feels the need to light up his light saber and strike down his nephew for a possibility he can turn bad? No. Wrong. 
Then there's just the force itself. Throughout the sequels and prequels, we are shown that the force is both light or dark. Good or evil. Now Grumpy old Luke tells us that's all bull####. There's no difference between the two. But then he gets upset when Rey "goes right to the dark." Makes no sense. Destroys the lore pretty much.