Essays can't really compensate for low GPA/SAT's. Also, Carnegie Mellon doesn't look at freshman grades, so doing badly in junior year could actually hurt you a lot. Here's my opinion of your chances based on each important admissions factor.
GPA: As far as your GPA goes, how is a 3.4 UW considered top 15%? Do you attend a private school or a really, really competitive public? If so, you're GPA will not be a problem. If not, it can really drag you down.
Course Rigor: I know that you're concerned about your GPA but you should probably be worried about your course rigor as well. Unless you're high school is super rigorous, 2 AP classes is not that impressive (I took 6 AP classes my junior year and I know a few people who took 7).
SAT and SAT II: Good job on the Math section, but a low CR score will definitely hurt you. Just because you're applying for engineering doesn't mean that you can get by with low CR and W scores. Nearly every selective colleges wants to see well-rounded SAT scores. SAT II's won't hurt you, but a lot of students at Carnegie Mellon have 800 on Math II. You might want to retake them if you have the time.
EC's: Excellent. Only problem I see is that you didn't do any science research or join any HS science clubs. CIT like science activites over math activites because engineering is more about science than math.
Hooks: First generation will not help you much if you have another sibling in college. If you're the first child to attend college, it can probably help you a little. Don't count on it too much.
Race: Keep in mind that you're an Asian male applying for engineering. Of all the different colleges at Carnegie Mellon, affirmative action is the most intense at CIT and SCS (there are just too many Asian males applying to both colleges).
Essays: If you're essays are as good as you think they are, then good job. I'm absolutely terrible at college essays, so I am envious at how confident you are in your writing. Again, essays can definitely help you, but it would be bad to rely on them exclusively. A good personal statement should make the adcoms like you AFTER they decide that they like your stats.
Now that I've chanced you, can you chance me? I'm also applying ED to Carnegie Mellon. Chances for Carnegie Mellon MCS ED?