Waterfall Glen sounds great to me. I'm not worried about my shoes on the trail, they aren't so thin that it would be an issue.
The Palos Forest Preserve is another good option. It actually doesn't have to be any further from ERE HQ than Waterfall Glen - there are entry points to the trail system even closer to ERE HQ than Waterfall Glen. I know this, because I live fairly close to one

. Always thought it was a good option, but a bit further for those coming from the north side, so never pushed it. I've traversed most of the trail system north of the Cal Sag Channel. Periodic restrooms (sometimes porta-potties), and at least 1 water refill site (Little Red Schoolhouse). Like Scott said, a mix of trail width, but on average fairly wide. This trail system is fairly involved so length can be scaled to desired length, loop or no, and small jaunts could be arranged if anyone wanted to join for part of the hike. And if we hike in the Palos Preserves/IM/Centennial, we'd be close enough to where I stay that I could probably arrange transportation if we do a 1-way path and need transportation back to starting point. All in all, if everyone is willing to do the drive it's a solid option to add in the queue.
Haha, I could see how Lake Geneva could serve to inspire the standard careerist Scott! Those houses aren't for me...but many were admittedly impressive by conventional standards. Enormous, giant windows, infinity pool/hot tub, fireplace with a lake view, private pier...there are definitely worse places to hang out.
That's fair Scott, I hope it works out that you can join for at least part of it, but if not that's a sign of progress on the jaw issue which is even better!