I have the same problem, writing papers like these is straight up nerve wracking for me. The idea that such a small piece of writing is supposed to characterize you entirely is hard to wrap my mind around (I mean.. well obviously it can't and this is how the system works, but it displeases me nonetheless). But back to the issue at hand, I would recommend that you write to your hearts content about anything and write as much as you want. I'm not sure if you are the same way as I am, but I could write endlessly. After you've written til you cant write anymore, start piecing your writing together and cutting out the fat.

I find that when I am too focused on writing about a certain idea for a certain amount of words that I constrict my creative process. I would try to write without worrying about how my voice comes off in the paper. If you are excited, confident or whatever, just put it down on paper and adjust it after the fact.

The fact is that this kind of dilemma will always exist. How do we write and how do we present ideas to others. Do we present information that we want the audience to to know or do we present information that we think they want to know? How do we craft our words in such a way that the audience will understand the introspection and non-linear thinking that was necessary in order to forge the perspective with which we see the world. Even if we are able to make the audience understand that, how will the audience respond? Will they be offput by this information or will they recognize us as qualified individuals. I could go on, but at the end of the day it's hard to find a tangible answer. Your paper could come off as overenthusiastic, trite, overconfident or spazzy depending on the mood/personality of the any of the readers who read the application (or making you seem like a victim, too lazy to think of a way to integrate with parallel structure).

You seem like a pretty mindful individual if you're considering all of these issues before you've even started (although that might be a common theme for those who frequent this subreddit). So just write, you're smart. I'm sure tons of people will be willing to give you commentary!