Wow.. Just wow. Everytime i see these theories about Rey being Luke's daughter, I think "what a boring and lazy option that would be".
Here is how I see it: Rey is related to none of the legacy characters. There is a reason for this. First off, we see Han take a shining to her, and this is probably because she reminds him a bit if himself and, likely, the child he lost. Han is feeling a bit empty and Rey makes him feel like a parent. Losing a child, in this case a different type of loss, a more metaphysical one, is the toughest thing ever I've been told. Han ran away from the only thing that likely made him feel he belongs. Rey rekindles that feeling.
Maz's comment about knowing the truth: has nothing to do with some force induced memory block and everything to do with denial. Rey wants to believe that her family is coming back, and they didn't abandon her. The truth is she knows they aren't coming. Her family couldn't and didn't care. You know who does care? The young stormtrooper that just met her. Who Chewie tells her it was HIS idea. The idea that someone she just met would risk his life to come back for her whereas her family abandons her is a huge, and important, point.
All this leads to the concept of "family". That it doesn't have to be shared blood that makes family, only that the people care about each other. What I see happening is there will be an epic showdown somewhere and Luke or Leia will choose to save Rey over their blood relative. Not in a vengeful way, but because this abandoned scavenger girl becomes more family than Kylo Ren did in his other life.
Bonus review: Leia and Rey's Hug. No blood connection there, but an emotional one. Leia is likely very empathetic and perceptive. She probably knew how Han had a fatherly ferling towards Rey, and seeing her so upset about the loss of the man she herself loved, she does the motherly thing and consoles Rey, another symbolism moment of family directed to this abandoned child. Leia was also not as affected by Han's loss as she had already Lost him years earlier, and this girl helped bring back, symbolically anyways, the Man that Han had become - the father.
Yes, i believe it would be a more poignant and interesting way to explore the family themed story by one of acceptance and belonging.
Good writeup, but as someone who worked in film and television albeit german productions I am a big cynic towards this. It is a great idea, but Hollywood or any other film biz aside from Indie companies will deem it not selling. It is basically the same thing why we have that blasphemy of a romance in the hobbit films: to sell it to other groups outside the focus group. Yes it is boring to make Rey a Skywalker, but it put's the butter on the table.
And in one thing I have to disagree heartily: you imply that a blood connection is not emotional? I have a deep friendship towards 37 cousins of mine, we meet every year and I love each of them dearly. We have fun together we meet during the year, too although in smaller groups and do something together, be it parties or travels. We give and gave each other emotional support, like when the mother of 6 of my cousins suddenly came out as being lesbian and always been lesbian and never wanting to see her kids again, we took them and my uncle in fo a while and helped them sort through the grief they had. And don't make me mention my 8 siblings, with whom this bond is even thicker! Don't sell a blood relation short!
As for why Han and Leia might not know about Rey: Maybe even Luke doesn't know about Rey being his daughter... Think about that.