What you can expect is an IE. It's pretty much the standard assumption that in your first year, you can't possibly be always meeting expectations, simply because you haven't been around long enough to have your feet fully under you/learn everything that needs to be learned, etc.
As to the other questions, I have very little experience (having never chosen to be an exec), but what I did see of exec scores, as well as my general impressions, led me to believe that Es were pretty much the norm, with only the occasional EX sprinkled in. Basically the same as the reviews for hourly employees.