There are lots of smaller parks that have one or two smaller coasters in the area of Chicago, some have indoor coasters and some have outdoor coasters. Personally, I wouldn't exactly want to ride the El for fun since it is currently under construction for like a long time now, the subway is closed and trains being delayed, not fun. Of all the museums in Chicago, I like the Shedd, the Planetarium, and Science and Industry the best, probably most for the kids to enjoy too. The IKEA, I have never been there, but it right near the Woodfield mall, which is a rather large mall and lots of stuff around there too.
When I traveled to IB, it took me about 3 hours to get there from my house in the subarbs, which if you try to avoid I-94 (Dan Ryan) and take side-streets, it'd be much quicker, unless traveling really early or really late. Also, in Chicago, you could always visit Navy Pier, that's free, but the shops and restaurants are somewhat pricey, the Children's Museum is in Navy Pier too. They have an IMAX theater also inside it, but it's like $12 a person to see a film.