How to pass -- just chill out.
I'm sure I lost the most points on my first case, where I was still a little anxious, and missed some obvious bad stuff that should've been on my differential but that I didn't think of until driving home. Once I calmed down and got into the groove, it was almost fun. (But I'm a sick person who kinda likes standardized tests).
There was maybe one case where I felt pressed for time. I was almost always out before the two minute warning, and done writing early, too. Time isn't really an issue if you've been in the hospital/clinic, as we all have been, and are used to being efficient. It's kind of a magical clinic where everything is on your side -- these are fake patients who answer direct questions with direct answers. They don't ramble at length. They're not drunk, high, or malingering. They're not struggling with English, nor are you struggling in their language. They are not chained to their beds with two officers guarding them.
Do you have the First Aid book? Maybe two reads through that, with a very quick perusal of Savarese, was good enough for me. I didn't actually practice the cases with real people or anything, so timing was what I was a little concerned about going in, but like I said, not an issue.
As for OMT -- I am no OMT superstar, and I still passed. You will know who needs OMT.
Finally, I had one patient where a MMSE was relevant, and I just put it in my plan. I think I did do some CN testing, reflexes, strength, etc., but an MMSE is too damn long and easy to screw up.
Also, for anyone reading this who is a third year still working on their fourth year schedule, I took this near the end of an ER rotation, which I'd highly recommend. It gets you used to working up a broad range of complaints with broad differentials, and used to being super efficient. I think family medicine might be good, too, but the Big Bad Things wouldn't be as fresh in your mental differentials.