It was for Chicago. Honestly, I thought it went well and the interviewer left a positive remark at the end ("You seem to know more about Chicago than the people I generally interview), but now I’m thinking it could have not gone so well seeing he hasn’t replied to my thank you email (and as in him saying in the interview, “It’s good to be passionate in something, but you have to realize like me that what you do in undergrad can be completely different from what you do in real life.” or in response to my passions and Why Chicago (third question in interview), which focused mainly on free speech, academic culture and core curriculum, he replied “Chicago is famed for its focus on Western civilization, so while you’ll get a good education in global studies, it might not be the main focus while you’re here… it’s important that you don’t look for a school because of the name value, etc”). Honestly, I don’t think I did a horrible interview because of the final remark he left and the fact that it went on longer than I expected (although 80% of the time he talked), but I have a feeling it could have not gone as well as it could have.
No
In the real world, people don’t respond to thank you emails with a you’re welcome email. It’s not necessary and it’s not expected. Read nothing into it.
There is no absolutely reason for the interviewer to reply to a thank you email. If you left the interview feeling good then I imagine it went well. I know this is a stressful process but don’t look for problems where none exist.