Didn't read this entire post, so sorry if I repeat what someone else sad.
Grew up in Chicago and went to the Field all the time when I was in college. (You get good deals to museums when in school) Now that I am out of school, went there for mother's day trip. DD17 loved going there with me when I was in school so I thought.... DS2 would love it too.... well I was WRONG! If you have a child that likes to do more interacting with the exhibits this is not the place, at least not for a 2-3 yrs old. We take my son to the Children's Museum all the time. I think he thought ALL museums would be like them, very hands on, touchy feelie.
If your children like history and cultures then the Field is the place. You chose your level depending on what extra exhibits you would like to see. The base ticket price gets you in the door, but if you want to see the baby mammoth you have to pay extra. There are only 2 places to eat, McDonalds (prices are higher than out side the museum) or Corner Bakery. When we went there was a hot dog vendor right outside the museum selling hot dog chips and drink for about $5. We ended up just walking along the lake front after about the 4th meltdown from DS2. He just couldn't understand why he could touch everything or why if you pressed a button some guy in a mono-tone voice talked about something he could care less about. Needless to say my DD17 was upset. She really LOVES cultures and history....
I think there is some Chicago pass citypass.com Go to explorechicago.org lots of great things to do on that site. This site has coupons chicagoofficeoftourism.org It also lists days that the museums are free!
Not sure about food to eat in the area. Restaurant change so much that what was good last week is gone today. If your in the area of Ontario and LaSalle street, eat at Portillios, it's a Chicago area restaurant chain. We love the food! Or try Uno's for pizza, also a Chicago exclusive, was stared on Food Wars: Pizza New York vs. Chicago. lol
Let me know iuf you need any other advice or suggestions. Happy to offer!