I have never been to the Iowa show, but it sounds similar to other shows I've attended in having issues.
The first thing I believe is odd is having the Auction take precedence over vendor selling being the 'first' day of the event. An auction should be a culmination or collaboration of an event, not a kick-off since it tends to gobble up the available money pool. Further, plenty of vendors likely want to bid on items so if they've had a chance to sell it means they'll have more money to bid with at auction, a win for the auction venue. However the Auction should not be the focus, vendors are the backbone of these shows and if they want to sell during the auction it is reasonable especially for people who may not care to bid on items currently being offered at that time of the auction, thus they could walk around and buy from vendors.
Promoters have the right and responsibility to police their event. If someone is selling early when the rules stipulate otherwise that seller should be removed immediately, period. Yes some vendors will be mad for being kicked out and say they won't come back, but if they are causing the problem then really is this an issue? Let them put on a show and have people cause issues.
We all know a lot of pre-selling and delivery occurs during these events. To reduce confusion 'pre-sold' items should be picked up during the event time rather than delivered onsite prior to start time. Exchanges well distanced offsite are of no concern. It's the use of the event 'out of event hours' that may cause rumors of selling when prohibited.
Weather is fickle, heat, rain, wind, etc; it generally effects the casual browser more than the diehard. This year it has been hot and that has had the effect on every venue I've attended since May.
Personally, mid-week shows are odd to me, and therefore a terrible idea for hobby shows where much of the participation is from blue-collar working people. It's fine if there are 25% able to take time midweek, but that means that 75% have to weigh the cost/benefit.
Most successful big auto shows I go to Wednesday is setup/vend-vend sales, Thurs is vendor setup/public sales, Friday is Vendor sales and Auction.
In the final analysis, if the promoters don't hold the vendors feet to the fire it doesn't matter how you rearrange the schedule.
