how big is the effect of needing aid on int'l?

Hello, I am international student that would like to apply ED, but I am hesitant to do so due to need aware policies. Should I leave Duke for RD?
I am from an underrepresented country. Would that help for duke?
Do I have a chance to receive Karsh scholarship with this stats?Nationality : Iranian ( though I am a mix of all major middle eastern ethnicities)
Intended Major : /Biomed/Biochem/neuroscience
GPA: I double majored in Junior year so I have two gpa’s: 19.20 for my theoretical major , 19.40 for my Experimental , 19.06 Sophomore, 18.76 Freshman. according to https://www.wes.org/gradeconversionguide/index.asp, all my GPA’s translate into 4 in the american system.
Course Load: Biology 3, Calculus, Physics 3, Advanced Algebra and Probability, Geometry 2, Geology 1, Chemistry 3, Persian Literature 3, Persian Linguistics 3, Islamic studies 3, Arabic 3, English 3, Contemporary History, Math for EXP majors.
ACT : 34 (34 34 33 34)
Sat ii : took it yesterday, predicting math 2 800, bio m 770+ and something good for Chem.
EC: Will graduate when I am 16.
English Teacher at a prestigious language college.
No AP or IB classes, as we all have the same curriculum in Iran. however, I was in a NODET (national organization for development of extraordinary talents) school, which means that our curriculum was tough as hell. however, I did have some advanced extra curricular classes in Math, Physics and Astronomy. I will probably write it as an academic EC.
Arts and humanities club member.
Internship at a very important Lens and Optics Lab.
part of high school National Computer olympiad team, no medal though.
9th at Ferdowsi Univ. Programming contest.
5th at Team Math&Chem City Contest
Fluent in English and persian, good at Arabic, Intermediate in French
c++, HTML, CSS, JS, PHP coder.
Web designer.
Swimmer, no awards though.
English,Geometry and Algebra tutor.
That is all I can remember right now.
Thank you for sparing the time to read my question.

Bump

If Duke is your #1 choice and you need financial aid, then applying ED is still a better alternative than applying RD. While Duke is need aware for international students, if you get in they will give you enough aid to meet your needs (assuming you check the box saying you’re applying for aid). So, of the alternatives, applying ED still seems like a better bet (unless Duke is not your #1 choice or you need to compare financial aid packages) and RD will likely be even more competitive. The competition for international students who need aid to get into Duke is definitely very high, but I don’t know of any statistics or way to quantify HOW MUCH applying for aid hurts a prospect’s chances.

I would think being from an underrepresented country definitely helps. Duke wants a diverse set of individuals and seeks students from across the globe. Applying from China is definitely much more competitive than applying from Zimbabwe. I don’t know how represented/rare Iranian students are at Duke.

You seem to have done well and accomplished a lot, but it’s really hard to say if you’d be competitive for the Karsh scholarship as there’s a lot of random chance in the process honestly. They look for certain things unbeknownst to me and want a diverse group of students – impossible to assess someone’s chances from just a few stats on an internet message board. They want to see PASSION and IMPACT.

You’ve worked hard and done well up to now. All you can do going forward is put your best foot forward and hope for the best. Good luck!

@bluedog thank you for your answer,
I am trying to decide between Duke, Princeton and JHU. I love all three, and it is really hard to choose one based only on interest. So I am trying to choose based on my admission chance. Princeton is need blind, but more selective, while jhu is need-aware and somewhat dry-handed with aid, but also is the least selective on my early shortlist. Duke is in between.