Your scenery.cfg it's fine. But, if it was corrupted, it would have FS9 crashing at start, or our installer not completing the installation.
If you are crashing only over O'hare, it must be something else. Usually is a default terrain texture missing or corrupted, or an AI with a wrong texture. Nothing related to O'Hare itself.
Have you tried with O'Hare disabled in the Scenery Library, but NOT Uninstalled ?
Just to be sure, you are running FS9.1, right ? 9.0 wouldn't probably work.