yes, could of, would of and should have
1. Taken the terminal transfer bus which goes every 15 mins on the secure side (https://fly-ord.com/connection-terminals) where you can use the FS or AC lounges. Bus works in both directions.
2. If you had a delay of 7 hours, I would have gotten a reasnable room, gone to pub or anything else that is better than the substandard lounge. Lots of options in the block if I had 7 hours up my sleave - could have even gone into Chicago and back by train.

Note - lack of invetsment is all due to the merry go round of terminal changes at ORD with the expansion (https://www.ord21.com/)