First of all, your book is simply awesome… I needed to get that out of the way. Your smashed burgers are just perfect (Fiancee agrees).

As far as your theory… I must say, I like the romanticism behind it. Yes, it’d be closing a poetic circle to have a Palpatine defeat the evil that spawned this whole mess. Yet I disagree with some of your points.

Let’s whack on two of them: Fighting style and Accent. Those two are (or should, speaking logically) be product of training and upbringing. I wouldn’t get too caught up with accents, even though I like the idea of having ‘the bad guys’ use a British accent, let’s remember that Star Wars is full of actors with a native British accent speaking with an American accent and vice-versa (Leia spoke with a [pretty bad] British accent at the beginning of ANH that magically went away as the series progressed. 
As far as fighting style…I don’t think that we can stretch the connection between Palpatine and Rey that far… we couldn’t even speak of a genetically-passed-on reflex to explain how their fighting styles are similar. I’d prefer to believe that since Rey runs around with a staff, she’s just used to grabbing the hilt with two hands instead of just one. And most of her movements are pretty basic in nature.

I am still trying to come up with a plausible explanation for myself about how on earth Rey is such a ‘natural talent’ with the force and fighting skills. Let’s remember how Anakin himself, the very spawn of the essence of the force wasn’t able to do squat other than an innate ability to fix things and good reflexes, and even after years and years of training he was only doing — so so — with anger management, lightsaber and force wielding. Same for Luke, after years of being aware of his powers he had to concentrate really hard to pull his saber out of the snow.

But after reading your theory, I started playing with the idea that Rey might actually be an improved ‘force spawn’ of Darth Plagueis.

As far as similarities, Anakin also grew up on a desert planet. (Though I am not sure if it was Plagueis who put them there)

Think about it… IF Snoke [Dear Lord, what a stupid name… it’s like Jar-Jar all over again!] is really Darth Plagueis, it just makes sense that he’d give it a second try at making an better, improved version of Anakin. Right? I mean the first try wasn’t half bad… But if that’s the case, it’d make sense that Rey would have an even stronger [native] connection with the force than Anakin, explaining her completely out-of-the-scope skills.

What if that was the case?

What if, let’s say, Han and Leia were the ones that discovered Rey, and they were the ones that took her away from Plagueis? And left her with one of Han’s contacts/buddies in a remote planet Like Jakku, hoping Plagueis wouldn’t find her? — That’d make sense and connect with your idea that Han was keeping an eye on her?( I like that! The thought about it being just a coincidence that Han picks her up over Jakku kept gnawing at me ).

I think that’d give it an interesting spin to the story.

What do you think?