The best -- not the cheapest -- way would probably be Uber. The info on public transportation is available in multiple online sources, via Google. I have never tried to get from Navy Pier to Willis Tower -- just never planned to. Have a nice trip.

I only walked to Navy Pier from the Mag Mile during the day time, or in the late afternoon (4 pm), never had any problems. Not sure about the evening, since it's not that very open walk way, both to and back from Navy Pier, some underpasses are involved in crossing Lake Shore Drive. You might call the city authorities and ask them, how safe it is in the evening. Or call the hotel -- they sure must know the best way to Navy Pier, not necessarily through Wacker Drive. (I walked via Ohio Street, that is fairly close and parallel to Wacker Dr). Or, just walk to the Navy Pier during the day/early evening time, may be? Enjoy your trip and Chicago!

I am sure that you can use your passport to buy liquor in Illinois because it is government issued piece of Identification that displays your date of birth. So, as long as you are at least 21 years of age - it should be o.k. to use your passport to buy alcohol/liquor.

no, they are not open at this time. and it is 'indefinite' as to when that will change

The taxi stand in front of Navy Pier is well lit and busy. You should be fine even late at night

Yes it does, unfortunately. The area cannot be accessed after 8pm by vehicle (taxi, personal vehicle, etc). However, you can get pretty close to the lakefront using LSD (Lake Shore Drive) and definitely take beautiful photos! Hope you have a wonderful night in Chicago!

book one of the dinner boats at the pier or one of the restaurants at the pier most have patio areas that are heated otherwise get there early or go to the 95th floor in the Hancock either the bar or dinner

While there isn't any free parking, there are ways to pay less if you're willing to walk a bit. The fee for parking at Navy Pier itself is $28 during the summer and $25 during the winter, but it's for the full day. If you want to pay less, you can eat at one of several participating restaurants and take advantage of valet parking. However, if you stay longer than six hours, you'll end up paying more than if you'd used the garage without valet! There are two official remote garages, and those charge $15. Street parking, while technically an option, is difficult to find and very expensive if you stay more than a few hours. Your best bet is to use a service like Spothero. During the summer you can park near the Magnificent Mile or the Loop and then catch the free trolley to the Pier. Or, you can walk the River Walk if it's a nice day! We've got a whole guide on our website. Google "Navy Pier Parking" and we're on the first page of results. (Can't include link due to TripAdvisor's guidelines.)

We took the Shoreline Tour for the Architecture tour. On this tour, you cannot get off or on at different locations. You board and depart the boat from the Navy Pier.

We were there in the evening and were mostly inside. I do believe there are benches along the pier. Not sure about bringing refreshments into the hall.