You have straight A’s and a superb SAT score, along with good ECs. I think that you are competitive for admissions anywhere.
Of course most applicants to Harvard, Stanford, and Chicago are very strong and competitive applicants. Even with legacy status Harvard is still a reach. It just might be a little bit less of a reach for you than it might have been for my kids.
For either ED or REA, I think that the main two questions that any student needs to answer are: (1) Is this school clearly my first choice? and (2) Is this school likely to be affordable for me? Perhaps there is a third question: (3) Is this school even remotely plausible for me? The answer to the third question in your case is yes. It seems that you have told us that the answer is also yes to the first two questions. In this case, go for it!
But, make sure that you also apply to safeties.
At least in our experience strong students (who perhaps were only slightly less strong compared to your stats) might not necessarily get into their first choice, but they usually do get into schools that are a good fit for them. Sometimes the schools get this even more right than the student does (in terms of accepting students that are a good fit for the school).
I would say: Apply to your top choices. REA to Harvard is a reasonable option. Also apply to safeties.
Another wild thought: Given your interests, plus some ability to speak French, I wonder about whether you might also want to also consider applying to McGill.