My biggest criticism is how yoda just appears, then gives Luke advice that he never takes. It was a completely useless scene. I feel like there was an editing mistake. Anyways, I would reorder it, just a bit.

Imo, this is how it should have gone down: Luke rejects Rey. She practices every day and he can see she is determined... maybe even warms to her (typical kung fu plot). He's put over the edge with the R2 scene and reluctantly agrees to train her. He senses darkness in her and is scared she doesn't reject it. He tells her the story of Ben's betrayal as a warning to her. However, he catches her talking to Kylo and flies off the handle. He suspends her training and tells her to be off the island by morning. While he's gone, Kylo tells Rey about how Luke was going to kill him. Meanwhile, Luke goes to burn the books and Yoda appears. Same conversation. Luke returns to a sleeping Rey. She looks up and there's a menacing Luke standing over her. She freaks out, remembering Kylo's story, but instead of attacking she asks, "Are you here to kill me?" Luke sits down and describes how he failed Kylo Ren in his moment of weakness. 

He explains there is light and dark in everyone, and the real reason he left and was afraid to train any new Jedi is that the temptation to go to the dark side was always present. She says she touched Kylo and believes there is good in him. He recounts his story in Degoba, warns he wasn't ready, but that she believes she can save him, she must always trust the light. Then Luke leaves the island with Rey and Chewy. You don't know what follows, but you know Luke is still teaching her (which helps her not be a Mary Sue).

It would also set up a better ending. Instead of Luke appearing by himself, he, Rey, Chewy and R2 come in the back entrance just as Leia has given up hope. He says he will deal with the threat, and orders Rey to assists with the evacuation (during which there is a landslide and she moves all the rocks to reveal the Millennium Falcon).

Luke doesn't use an astral projection: He actually does what you think he does. I really liked the idea that Ren could not touch Skywalker with his lightsaber. I think it would have been far cooler for Luke to be there in person and have that power. Let Luke show Ren he was powerless to defeat him, maybe even putting his saber to Kylo's neck a few times, but not harming him. I would have liked him to wait until Ren's lightsaber was in his heart for Luke to say something like he did earlier (you will have to carry my death like you carry your father's), before looking off to the horizon and giving himself up. Leia and Rey feel him pass, as they fly off in the Millennium Falcon. 

To tie up a couple loose ends, I would have preferred Fin, Poe, Maz (not Rose), and BB-8 infiltrate the star fleet to harass their communications and weapons (instead of the lame excuse that the rebel ships are too slow). Being a menacing force on the dreadnought would have been a much cooler side quest and been reminiscent of the old star wars. The cat and mouse game between Phasma and Fin would have been much more enjoyable. Also, this takes away the need to keep Poe in the dark. Instead of him being the stupid, hot-shot jock, he is in on the plan. He can still learn his lesson by losing some extras (maybe Rose) on the mission. Lastly, let Fin sacrifice himself for the rebels. It was going to be such a powerful scene and they just took it away. Super annoying.

I could do this with the whole film, for example, it would be easy to make Snoke's death more meaningful, but what was stated above are necessary. The movie would have gone from OK to really good with those changes. I'm not convinced Rey's parents are nobodies or even that Snoke is dead, but I could accept that at face value if Luke's character remained in tact. I really don't feel like it's that hard to make a good movie, but Hollywood has lost touch with story-telling.

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