I just had an interview day during which I was interviewed by all 6 faculty in a (small) PhD program. the program chair organized the interview and led it, but each faculty member asked 1 or 2 questions, like a panel. Afterwards I went to lunch with a group of students. Since I really wouldn't have much to say in an individual note to all these people, is it appropriate to write one hand-written note to "Dr. [name of program chair] and the faculty of XX program?" And just write the letter addressed to the faculty as a group saying I enjoyed the interview and learning about the program, etc.? I could also do the same for the students, write and/or email them a group thank you note?
Thanks in advance for any advice, I'm so self-conscious about these things for some reason!