i think you're not going to get a good sampling here on SDN in terms of what scores and grades you need. take a look at the most recent charting the outcomes of the match from aamc. that should give you a good idea. avg step 1 is prob around low 240's now and about 1/3 of applicants are AOA. almost everyone has some sort of research. research does not equal publications, though. obviously it's great if you can get published but it's hard to do, especially when you're in med school. i met a lot of people on the trail this past year who had research but not publications. obviously some programs highly value pubs and that is a significant criterion for those places, but i found that most places are happy enough with applications showing the dedication and interest to at least involve themselves in research.
for those who do not have an ENT program at your school, that kind of stinks, to be honest. if anything, you really want to make relationships with attending otolaryngologists so you can get letters of rec. i think that's the biggest negative of not having a home program. if you cannot make contacts with attendings during your third year, then i think it's of paramount importance for you to do an away rotation right at the beginning of 4th year. letters are a huge deal, prob more important than research, i'd have to guess.
for those of you worried about research, you don't have to have breakthrough basic science pubs. case reports aren't great, but they're something. if anything, it really shouldn't be difficult to get involved in some retrospective chart reviews. this is totally doable as a third year student. don't discount research you've already done that's not in ENT. that is not worthless. the key is to be able to discuss it intelligently and concisely at interviews.
lastly, i'm an advocate of away rotations. i did one and matched at that program. also, almost every person from my med school who matched in ENT matched at the place where they rotated. just make sure you do a good job. easier said than done. show your interest without being annoying (some people don't get this). be smart about things (read.. a lot). be helpful (have tongue blades on rounds... change dressings...). be professional, but also be likeable... one thing you're being judged on is how well you will fit in with the current residents/attendings.
none of this is novel, but hopefully it's helpful. best of luck.