Undergraduate / "Roommate, I promise to do my best to accommodate you" - Stanford Essays [5]

Hey, everyone. I'm currently in the middle of submitting my application to Stanford university, and I'm in need of some opinions on my supplement essays. But first off, I'd love it if someone could answer a question about these essays for me. I've been writing them with a 250-word limit in mind (as that's what Stanford's website said the limit was,) but now that I've actually began work on the Common App website, it seems as if we have 1800 characters to work with. I'm wondering if anyone could tell me which limit to adhere to?

With that out of the way, I'll begin the supplements by posting my response to the second supplement first (I figure I'll just edit this post to include all three when I finish with them, rather than creating three threads, if that works.) But this essay is in response to the following prompt:

Virtually all of Stanford's undergraduates live on campus. Write a note to your roommate that reveals something about you or that will help your roommate-and us-know you better.

My response

Dear Roommate,

In order to ensure a positive relationship between us, I decided to deviate from the "prompt" of this letter, and introduce myself through something I believe to be far more practical: a list of promises that I swear to uphold while we're rooming together. Promises that, I hope, will allow us to get along like proper roommates should. So, in the interest of a better future:

I promise not to keep you up until 3 AM while I cram for tests, play video games, or browse the internet. That is, unless you're up until 3, cramming with me.

I thoroughly enjoy listening to trance and electronic music, but if you don't, I promise to listen through my headphones, instead of blasting it.

I promise that I won't return to the room and prattle annoyingly about whatever new way my professors had discovered to shatter my conception of the world.

Considering how much of a dork I can be, you shouldn't have to worry about this one very often, but if it should come up, I promise not to bring girls back to the room.

Lastly, I promise to do my best to accommodate you. I have an extremely flexible personality, and should any facet of it ever bother you, I'll do my best to fix that part of it. I figure if we're spending the first real year of our life living together, we may as well do it as friends.

Sincerely,
Your new roommate, Michael Werner

What made me deviate from the prompt was that I figured this supplement was really focused on giving the applicant a chance to have their personality shine through. I hoped that by doing so, I'd be able to show a bit of my personality whilst still advertising the traits I would show as a roommate. Thoughts?

Thanks in advance, everyone! What a cool concept for a forum.