Sorry about the rejection, smmypnts 🙁
As for determining culture and fit, you have to be vigilant and also have a good sense of who you are and what you want. I did my homework and read through the websites of a ton of schools. On secondary applications, I took note of what questions each school was asking (or not asking). I actually didn't submit secondaries to a few schools where I thought the questions were not important or relevant to how I wanted to be evaluated as a candidate.
On my interviews, I paid close attention to details big and small. At one school, I got a tote bag with the school logo and had an interview with a visiting alum. This school obviously makes a big effort to promote its name but also seems to do a fine job of creating a friendly and collegiate atmosphere and a strong network of active alums.
At another school, the dean gave a heartfelt speech about service in medicine; however, none of the students I talked to expressed a similar sentiment. Rather than giving scholarships based on service, the financial aid dean said that they give scholarships to students who have very high numbers to help raise their rankings. It made me question whether or not the school was truly dedicated to service as well as the the competency and/or efficacy of the administration.
At the end of the day, I was accepted to the places where I thought I was the best fit, waitlisted at the places I thought I was a partial fit, and rejected from the one place I did not fit in at all.
For me, I didn't think the application process had much mystery or very many surprises (though BU was a bit of a surprise because of the extraordinary number of applicants). I knew what I wanted, I painted an honest and coherent picture of myself in my applications and interviews, and strongly considered the values of and culture of each school before applying.
Good luck with your other applications. I hope you find a school where you're a good fit and can be happy.