Yes. Its better to directly contact the tower for questions like this.
Yes, I would recommend you do the expediate tour. It is a bit costly, but you bypass the long lines and the wait for nonexpediate tours are long.
Yes. You have book your tickets in advance. And everyone does shows up. Keep in mind there are 4 sky decks in Chicago. You want Willis tower
Yes. 50 people at a time are allowed in the space.
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