You've gotten a lot of good suggestions there Ed, maybe you'll need to setup a survey people can take. SurveyMonkey.com is a good tool for that.
I can't remember but is there a tram running around the event? It would help people get around to different areas or even back to the gate. If there is, maybe you need more.
Also stress to the food vendors that there are many people there at the show who don't get a chance to get something to eat UNTIL everyone else starts to clear out. They rake in the cash when it's busy so they could stay open a bit longer for those who couldn't come by during the day.
