I've taught and checked in the sim and on line.
I've always thought, you can have great skills and a poor attitude and get through (although the attitude part doesn't give anyone a warm fuzzy about you one day being a Captain).
You can be weak in skills and have a great attitude and make it through.
If you have weak skills and a poor attitude, you're not going to make it through.
I agree with the above statement. I've had many pilots, both new hires and upgrades, tell me they're pretty nervous at the beginning of IOE or OE. I always told them, "That's good, it shows you have a clear understanding of the situation." I would also agree that the people that are smart enough to be a bit nervous rarely have any problems with the process.
The sim is all memory. Callouts, Flows, Profiles, Limitations and Memory Items are what you need to start the sim. Procedures, abnormals and applying the book are part of what you should be learning during sim training and on into IOE or OE.