For another data point, I chose a word document with a couple of pictures for the primary application, and also chose option 3 for the additional essay. I am a serial googler of things so I felt it gave me the most direct route to showcase my personality of the 3 options. And I felt directness was key with a 250-word limit.
For the folks flying in for an interview, I would recommend staying somewhere between mag mile/gold coast and McCormick Place (if there is no convention in town during your interview, the rates would probably be reasonable for a decent hotel). The uber/lyft/taxi commute from downtown is much easier and less traffic prone than from either airport, and you would have more food/activity around you than if you stayed near campus.
Best of luck to everyone on their interviews!