Hesgesmfg, wonderful post! Not much else to say about it but I appreciate the thought and articulating what I often try to go for.
I think it’s best to leave both the TLJ “It was I who bridged your minds” and TROS “I have been every voice” lines alone.
Trying to ignore the non-film material and chatter, here’s what I imagine piecing together from perhaps multiple viewings: Rey is essentially a neo-chosen one, gifted by the Force in a time of need. Destiny brings her to Kylo Ren, and the two find themselves at a stalemate. Snoke comments that they are equals on either side of the luminous divide. They each spiral around each other, attempting to draw the other into their place. Snoke takes credit for this, though he’s clearly playing with powers greater than himself as their connection persists past his own death. Palptine appears and tempts Ren with the idea of he and Rey forming the alliance he tried for once before. Rey senses and fears the same. Kylo presents her heritage as a trap, which Luke reverses as he did before on Crait. Rey and Ben join, each briefly fulfilling their desires before the latter fades away, the Force investing itself now fully in Rey.
Rey is no one. She can’t stop needing her parents, believing they’ll return one day. She comes to discard this belief, turning her attention to Luke as a surrogate. He fails her while she learns to rise above questions of the past. With a broken blade she wonders how to build herself up after the necessary deconstruction that has taken place. Now, she fears her own darkness that now has no container and wonders if the lack of defense mechanisms may let out something terrible. Kylo facilitates a demonstration to confirm this, sacrificing Chewbacca. Rey is forced to revisit buried memories of her parents, finding that they loved her after all but were taken from her. She also learns that she is the progeny of a hitherto not immediately relevant bad guy, reinforcing her fears. She goes too far once more and exiles herself in order not to test herself and risk unleashing darkness which had frightened even Luke. She resolves to venture into the darkness to bring it illumination and take the risk. She finds Palpatine’s offer tempting in order not to lose those whom she has come to love, and joins with Ben to defeat him. She falters and passes after giving up herself to fight the darkness, though Ben’s redemption provides a surplus which he uses to restore her. He has now healed her in return, and she proceeds to bring the elixir of balance to the galaxy.
Weakest point to me is the Palpatine lineage, as this seems only to muddy the water and give the audience a big dumb thing to follow along with, short-circuiting nuance. But don’t worry because there absolutely will be two versions of the project, one for both heritage possibilities for Rey.