I good friend of mine came by one day and ask me a question:
Is Rey a Mary Sue character?
We then ended up in a 3 hour conversation where we discussed, the star wars trilogy, droids (one of my most favorite cartoons of the 80s as shown by my "was c-3p0 a hero" article), marvel superheros, the prequels and finally Star Wars: Rebels.
My good friend had never seen it before, so I sat down and watched the first two episodes. Once done, I asked if Ezra was a Gary Stu despite of being in a very similar role.
I admit Ezra is essentially "space Aladdin", but I think Ezra comes out a stronger character overall and this is why.
1. Ezra is flawed: His beginning scene that connects him to the party is a screwup. He's a skilled street rat that immediately steals the supplies that the Ghost crew is trying to steal.
2. Ezra fails: He gets into as much trouble as he gets out of.
3. There are other heroes fulfilling niches: I have issues with Ezra hogging the spotlight and he's not my favourite character on the crew. We don't get that from Rey. Poor Finn rarely succeeds in what he does, and Rey Latching onto Han feels very Mary Suish in it's results.
In contrast, Rebel's has Kanan, Hera, Sabine, Zeb and Chopper, whom all feel different enough as new characters, skilled in their own ways, yet still containing their own baggage and story arc. Hell, I could watch an entire series focusing on Zeb and Sabine as they have this weird big brother/smart little sister vibe that's a blast. :)
Heck, I even liked the additions of Ashoka and Rex as semi-regulars from the clone wars.
In spite of this, I am willing to give Rey the benefit of the doubt for the following reasons.
1. I'm convinced Rey is already trained at padawan level, but is repressed. That would explain the flashback.
2. I believe Han and Chewie should have found Rey and Finn on the planet and then found the falcon. It's in complete disrepair after being stolen, but Han puts the kids ("stowaways") to work as the ties come flying down. that gives Rey and Finn some transition time to get up to speed. shows off Rey's repair skills while flying and Finn's skill firing, while Han and Chewie control the flying and I think there wouldn't be an issue in the world with the scene. plus then have a quickie scene where Han basically recruits them and tests their skills.
3. The more I look at the lightsaber scene, the more I realize Han shouldn't have died until the next movie. besides losing a chance to reunite the classic trio, it gives a chance to lay down a failed attempt and force Han to return a failure to Leia, increasing the pathos and making him more reckless that lead's to his death in the next movie.
4. That being said, the final scene makes more sense as kylo falls apart because of his actions and it honestly makes the final scene more digestible.
5. I'm seriously agreeing that the scene we should have seen is a dusky night where a large wookie hugs an elderly princess as they share in their grief. no words would have been necessary and it would have had more emotional heft then the scene that was given.
I don't think Mary Sue is the right term for Rey. More like a Samantha Carter :p.
However, I will reserve judgement until the trilogy is completed. We don't have enough info to confirm at this point.