Is there a way to see only the classmates who have been verified?

"Sort of" I think is the answer to your question.

From your Preferences area you an see a list of Classmates who are awaiting verification. Presumably you're verifying anyone on that list pretty quickly and not leaving them on there. If that's the case, when you go to your Classmate Profiles page just click the link next to the green checkmark in your key, and that will give you a list of your participating Classmates. Sorting your list like this is going to also include Classmates awaiting verification if you have any, so it's not quite a "verified only" list (unless you have no Classamtes pending verification, in which case it is), but it should be pretty easy to deduce who on that list is not verified, since I'm guessing the # of Classmates on your Awaiting Verification LIst is usually small or none.