I don't know how formal nih and fda interviews are, but for interviewing with a prof at your school, a suit is overkill. Go with some nice pants and a decent collard shirt or dress shirt, with nice shoes of course. As for preparing for the interview, you should definitely read up on some papers, and try to get a general understanding of what the prof is trying to figure out. They really can't expect you to know too much, but you should at least be able to talk about why you may be interested in their research and be able to ask some intelligent questions.
You could talk about the possibility for publications, but you have to be real careful in how you bring this up. Personally, I wouldn't bring it up, just because you don't know how the prof will take it. Most shouldn't have a problem with talking about your chances of a pub, but there might that one guy who thinks to himself, "this must be one of those annoying pre-med who cares not at all about the actual research, but only wants to strengthen his application with a publication." But since you've already brought it up, just go with it. Honestly though, a publication, while nice of course, should not be your ultimate goal. Your goal should be to learn how to think scientifically, and learn how to approach different sorts of problems, among other things. Now, if you truly do have no interest in research, then yeah, just feign interest and hope you get that publication. I'm not saying that this is the case for you though, although personally I don't think its that wrong even if it is the case. Med school is a tough competition, and a pub certainly helps.
Good luck 👍
