http://inlikeme.com/admission-statistics-acceptance-rates-early-vs-regular/
Based on this article you have a fairly decent chance. Since you are an international student (taken the A-levels…British, right?) that is in your favor, since F&M likes a diverse background. What might hurt is the international student financial aid, which is terrible at other schools. However, I hear F&M has one of the best needs-based aid in the country, since they got rid of merit aid (you can google this one). Here’s the link for F&M int. student aid (might help): http://www.fandm.edu/financial-aid/international-students
Hopefully you will get in because this year according to F&M’s Facebook page, “Thus far, the Franklin and Marshall College Admission Office has counted 7,025 applications from students seeking places in the next first-year class, an increase of 25 percent over the previous record of 5,632, set in 2008, and 28 percent more than last year’s application total of 5,472.” The old (2012) acceptance rate for F&M was 39.3% (When there were 5500ish students applying), which means that the new acceptance rate is just above 30%. If a lot of those students are ED2, then it’s going to hurt you, otherwise you don’t have to worry about it, unless you get pushed back to Regular Decision. I applied to F&M regular decision (changed last second from ED2), which is why I know most of these facts (research).
Also, F&M has an SAT optional option (if you know you’re an better writer than test taker) where you submit 2 writing examples, but you might not be qualified: https://edisk.fandm.edu/occ/magazine/spring05/sp05_story1.html
Profile wise, your GPA and SAT might be a tad bit under average or average, but F&M has a “holistic” admissions process. This is when they look past your scores, and they focus on schedule-rigor (you’re very above-average), Leadership & EC (again, you’re unique here too), and diversity (you’re an international applicant, so that’s a big plus). I know I shouldn’t be helping out the competition, but you’re an ED2 candidate that sounds much more interested in F&M than me. Best of luck and hopefully you get in!