Firstly, this is a great thread. Thanks for taking the time to do this and congratulations on on the outcome of your app cycle! I know how exciting it is to be happy about where you're going!
I definitely want to reiterate your point about being honest. I had a pre-health committee interview at my school, but aside from that, I never went through practice interview questions or rehearsed any answers. Instead, I did a substantial amount of self-reflection before I hit the interview trail. To everyone preparing to apply, you should be intimately familiar with all of the experiences you've listed on your AMCAS; I'm pretty sure all of my interviewers throughout the season have asked me to expound upon a meaningful experience related to an AMCAS activity.
On that note, I also think it's fine to take a moment before you answer an interview question to compose your response. At one school where the questions were all particularly bizarre, there was one instance where I actually asked if I could have a minute to think my answer through. Afterwards, the interviewer commented that he appreciated my taking the time to be thorough and he thought I seemed very genuine. Regardless of the question, always think through your response and check yourself often to ensure that you're actually answering the question that was posed. If you interview at a school that uses panel interviewing, you'll see the importance of this; there's nothing more awkward than sitting through a group interview while another interviewee fumbles around with prepared answers to distantly related questions.
Lastly, I want to share questions I posed to my interviewers that I think they found engaging:
What brought you to <school X>?
This one's good because it gives the interviewer a chance to talk about themselves a bit. You can likely also get some insight into what qualities the school possesses that might be particularly attractive to you. This question also generally permits for a lot of follow-up questions.
What are some qualities that you think the students at <school X> possess that make them stand out from other schools you've worked and/or trained at?
This one was my favorite and I think the interviewers liked getting it because they had to actually think about it. You can comment on their response and maybe sneak in a comment about how you are similar to the students there and think you'd fit into the school's community
Good luck to everyone getting ready to go through this process! Like NickNaylor said, it's long and horrible and will make you feel like absolute **** at times. Be honest and don't dwell on the things that have already happened (don't think about how your interview went afterwards - you can't change it!). If there's anything I can do for anyone in the future or if anyone would like to PM me with questions, feel free to do so.
