All the things you listed and didn't (t-shirt, sun visor for car, backpack) plus mounds of information in a folder about the school, its match stats, curriculum, schedule, etc. Since you are an Adcom and not in the Admissions Office who generally decides on what to provide applicants, I am guessing you don't have a say in what is provided to the interviewees?
Personally, I don't see the point of all the swag. The information folder is more than enough. I doubt that I will be persuaded to go to a particular school if accepted because of a school branded stress ball.
And since I am generally not a "stuff" person, I feel forced to accept the swag bag for fear of being labeled as being uncooperative. So I reluctantly take the bag.