Have to go to the outer roadways on the upper level to smoke in O'Hare. (You'll get this once you get there)...

There are no more smoking lounges inside the airport. On a Sunday afternoon, assuming you have no status, it should take maybe 30 minutes to get through security on a bad day. Terminal 1 especially has plenty of security lines that are well laid out. T2 and T3 are slightly worse, and I've never encountered problems at T5.