Using 'Potential' in Fiction

I have an idea that I want to explore in fiction.
I want to write a story that perceives a real-life experience unfolding in a different way than it actually will. It would be as though I was planning the future. In a sense it will mimic real life and then take a different turn, and series of turns, based on the altered arrangement. Here are the ideas that I want to sort out in this manner. What follows will likely be notes just to help me organize my thoughts.

I have a friend in prison named (XXX). I don't want to talk to her anymore. Or at least I don't want her to know that its me talking to her. So far, there is too much expectation for our friendship. We were friends before the murder. Now, the friendship is expected to last all twenty-five years of her servitude. This kind of sentencing doesn't work for friendships. I need freedom, freedom in my approach.

There is a girl in my neighborhood who I used to live with. Her name is (YYY). I grew to despise her during the three years I lived with her. We came from different backgrounds. She was from Israel and I don't think that's why I didn't like her. It was due to more specific reasons, but perhaps they were tangents off of an ultimate unwillingness on either of our parts to 'transcend' culture. I have her address, I have her name.

I would like to arrange my letters to XXX as though they were coming from YYY. I've been meaning to send her poetry, perhaps with little written commentary about each poem and why they are important to me. It would be the strangest written relationship because it would be a letter writing triangle of mishaps, probably resulting in a cluster fuck. I imagine it would unfold something like this: I write from YYY's address. XXX responds to YYY at her address. YYY doesn't know why she receives letters from XXX. She might write to XXX to try to stop the letters from coming. XXX would be receiving mixed messages from YYY. The mail authorities at the prison might start to be concerned about the double personality of YYY's address and name. They might send letters back to YYY unopened. YYY would receive my fake letters in her name. YYY would investigate. Because that's the way YYY was. She would be scared, because she is neurotic. They wouldn't be able to trace the letters to me, because I would drop them in the nearest mailbox to YYY and I would type them and print them on clean paper, folding them with gloves and taking the utmost care to leave no trace of 'me' on them. Perhaps the mail people would get involved. How many mail crimes even happen these days? Very few I'm sure.

The result of this would be two-fold. On one hand, I would have a mode of expression to reach XXX without expectation, without her knowing its me, allowing her to develop something that will soften the blow of the fact that I don't want to talk to her as 'myself' anymore. On the other hand, I would have a chance at revenge against YYY. This mail-crime would be a labor of love (and hate) all for the sake of poetry.

The only thing to do, is to try it.

This is where the story would begin