Hello!
Exams first year are about once a month. There are two classes per unit (anatomy and histology is the first block, for example) and the exams are scheduled kind of around the same time as each other with some variation. Exams second year are every 2 weeks pretty much, also with variation. We had microbiology and pharmacology this year together to start the year, so we were getting an exam every Monday, but that exam schedule will change for the class of 2017. Once pathophysiology starts we are examined as often as that unit allows. So cardiovascular had a month for the unit, dermatology was one week long, etc. Also scattered throughout our schedule is physical diagnosis and some other ancillary requirements. Stress is pretty individual I would say. Consensus was that our schedule at the beginning of the year was pretty brutal (I am in second year, just in case you didn't know) but I didn't really start to feel real stressed out until our neuro unit, for whatever reason, which was about a month ago now.
We are ranked internally I suppose. First two years of school are on a H/P/F system and each course takes one standard deviation over the class mean to be the honor rate. Sometimes the honor rate is slightly less than that (few z score points below) but that is pretty much the benchmark. Honor rate is what you make of it. I have not had any negative interactions with any of my classmates, and am a pretty live and let live kind of person, so if someone is stressed out cus they want to honor stuff and works really hard accordingly, I don't really see how that affects me at all. I have not heard of any true "gunner" activities in my year, where people were trying to sabotage each other or anything like that. I do personally think it is difficult to honor stuff but it doesn't mean its impossible. But, personally, I have found that whenever I really put pressure on myself to honor a particular exam or block I tend to do worse because I am focusing on getting a particular grade instead of getting as much knowledge as possible and doing the best I can. A friend of mine goes to Michigan and while they are only pass fail in the first two years, they do have honors in third year (they have to come up with AOA list from something, right?). This is anecdotal of course, but he told me that the collegial atmosphere of Michigan tends to dissipate once honors come into the picture. At Wayne, everyone can honor clinical years if they really wanted (it's the reverse of the Michigan situation), because it is based on shelf exam score and clinical evaluations which theoretically everyone could totally knock out of the park. So to me it's just a different approach and Wayne is more known for its clinical years (than its pre-clinical curriculum) anyway.
EDIT: I wanted to add some stuff. You asked if most people try to honor courses. In a class of 290 people, it's tough to say if "most" people are doing anything. I would say that there are solid contingents of all kinds of people .. people who are fine with the pass, people who are rock solid in the middle no matter how much they study, people for whom honoring is no big thing, people who work their butts off to get that H on the transcript, people who totally slack off and do okay, people who work their butts off and barely squeak by. If you are trying to get a sense of the atmosphere at school, in my experience I would say that every class works a little differently. The personality of your class, no matter where you go, will be defined by the people in it including YOU, so you have at least some small part in the culture of the class. My attitude is that we are all in this together, and competing against each other doesn't really do anyone any good, so I try to live by that message and not be a d-bag to other people and pretty much try to support their efforts or at least don't cut anyone else down. Stress is real, though, and I am sure it abounds at different times at all medical schools regardless of how things are graded.