Plo Koon was able to conjure lightning.
The T-65 may have a navicomputer on it, much like the Falcon or any other ship. We can assume they have some sort of computer to make the calculations, as the A-Wing and B-Wing were able to jump into hyperspace and they have no astromech droids.
The EU had plenty of terrible plot points. Luuke clone created by Jorrus C'baoth was up towards the top of that.
But overall, I agree.
Where Disney failed most of all was fasttracking Rey's training. She went from living in a broken AT-AT to having supercharged Jedi power. She had no training and no instructor, and tapped into something she had no knowledge of to overpower someone who trained under a the highest ranking Jedi Master, then a powerful dark side user. Luke couldn't best Vader until the end of the third movie, after working with Obi-Wan who introduced him to the force, and the last leader of the Jedi order in Yoda. One can assume that once Obi kicked the bucket, he still visited Luke between the events of ANH and ESB. The length of time Luke was on Dagobah is up for debate. The official word from Lucasfilm in the old RPG game was 18 months, the most recent number provided is around 6 months due to time passing slower on Dagobah. Disney gave us a character who was given powers that every other character we have seen has had to train for the level of power attained.
Disney needs to explain this in ROS. And "she was the granddaughter of a powerful force user" isn't good enough, as Luke was a son of the chosen one and still got shot by the training droid on the way to Alderaan.