Assuming you are student BODY president (which would be pretty nice)…
I think high match/low reach for all but Stanford, Yale, (maybe) Brown. Translation: pretty good chances at getting into a couple of your dream schools from my perspective. Do retake the SAT and try to score 2300+. Try to secure a leadership position or two more from your clubs. And I personally don’t support your idea of creating a Model UN team (hard to do, plus it looks like you’re trying to fill up your app since you waited until senior year to do so) - unless you love international relations and Model UN, then of course go for it and do what you love. that’s the thing, never let anything stop you from doing what you love (ok, I’ll stop, this is getting cheesy). Good luck!
http://talk.collegeconfidential.com/what-my-chances/1752114-predict-me-game.html#latest
^shameless self-advertising