I am pretty sure that this has no impact on admissions.
First of all, your ECs do not need to have anything at all to do with your major.
Also, I see music (specifically violin) as one of your ECs, and it looks like you put in a lot of effort over a period of time and did very well. Music ability is something that often overlaps with math ability, and math is something that is very useful for a CS or Finance major.
MIT does not admit by major. ALL that they use your intended major for is to match you with a freshman year advisor (if you are admitted, and if you choose to go there). That is all that they use it for. In the unlikely chance that you are admitted and choose to go there, then you might as well have a freshman year advisor who is more knowledgeable in at least one of your intended majors. You are correct that MIT students then get to pick any major that they want starting sophomore year (I am pretty sure that I picked my major towards the end of freshman year, but it did not take effect until sophomore year). As an undergrad at MIT you can also change your major any time that you want to, but you need to complete the requirements for whatever major you end up with before you graduate.
MIT has a major 18C āmathematics with computer scienceā which to me makes sense for someone who is undecided between CS and finance.
I think that some other highly ranked universities are the same as MIT in terms of not admitting by major, but you might need to check them individually. Regardless, having some ECs that do not match your major is fine and is perfectly normal. It is more important that your ECs show the ability to do something well with a commitment over time and the ability to get along with people.
This is very good. This is low for MIT or Stanford or Princeton.
Similarly your SAT is very good. However, as I expect that you know 740 in math is low for MIT.
Picking solid safeties may be the most important part of picking a list of schools to apply to. Depending upon how you feel about your safeties, picking targets might be the next most important part. However, I expect that many or perhaps most students have in-state public universities for their safeties.
I do not know whether TA&M is a safety for you. IF it is, then it is fine for the rest of your schools to be reaches although I usually prefer to see two safeties. Your guidance counselor should know better than I whether or not TA&M is a safety for you. UT Austin might be a match, but admissions to CS is uncertain. Otherwise I think that these are all reaches.
And this is very true. Do not pick a major that you donāt want in an effort to game the system. Instead, pick whatever major you expect is most likely to be the one that you intend to stick with. Being genuine is very important when applying to highly ranked schools, and is important in life in general.
I do not think that it is luck. Some of it may be factors that are beyond our control. Some of it is the schoolās perception that you are likely to be a good fit for the school. As one example, if you pick an intended major that they are actually good for that might help your chances. Some of it is academic excellence. Some of it is excelling at something, even if this is not academic and not something you will pursue (if you for example excel at sailboat racing or chess or violin any of these might help even for a potential math or finance or CS major). Given that highly ranked schools end up having to choose a few students to accept from a very, very long list of very well qualified applicants, some of it may appear to be luck.
I was a math major at MIT. Quantitative finance is something that math majors sometimes go into. Basically you try to apply mathematical models to understanding finance, such as the potential movements of stocks. Mathematics actually gets applied to a lot of things (acoustics, aiming a beam of subatomic particles in a cyclotron, economics / econometrics, Internet security, finance, ā¦). Understanding stock market movements is one of the many things that people can do, or try to do, with a degree in math.
I think that you are generally doing very well. Make sure that you apply to solid safeties, and I expect that you will do well wherever you end up (even if it is most likely to be TA&M, which is a very good university).