Too many times I see students overweight the importance of EC’s. Unless you are a national level winner/finalist in some type of well known contest or unless you are an athletic (or possibly musical or artistic) recruit, EC’s are pretty far down the list of importance by themselves. EC’s are used to round out the story of who you are, and gives the school an idea of your energy level, ability to commit, perseverance, leadership and other desirable characteristics. Looking at your list, I would say it is pretty typical of the list competitive candidates for Yale would have. What will be critical is how your EC’s tie in with the essays and rec’s that you will submit, and to a much lesser extent, how you can use them to create a memorable interview.
On the Senator’s recommendation, if it is a “generic” this candidate is smart, ambitious and would be a great asset to your school type recommendation, it won’t be of much help. It needs to be specific with personal knowledge of facts and circumstances that back up the compliments. https://admissions.yale.edu/supplementary#recs Yale is really looking for 2 great teacher recommendations https://admissions.yale.edu/instructions#recs.
Yale is a reach for anyone. However, you will not even be in the “game” if you do not meet a basic threshold of academic achievement as measured by your GPA/class rank, rigor of coursework and standardized test scores. https://admissions.yale.edu/what-yale-looks-for As far as your B’s are concerned, 95% of Yale freshmen in the Class of 2020 were ranked in the top 10% of their class. I would hazard a guess that a vast majority of those were in the top 5%. The 25th to 75th percentile for ACT scores is 32-35.
Finally as a URM, you will get a boost. How much is a big question. I believe that the admissions counselors are pretty savvy these days and distinguish between URM’s. Are you first generation, likely family income level based on zip code or other indicia in application, immigrant, etc… all factor in.
Good luck.