There are many experienced racers at Lemons. I've friends who race the Lemons/Chump series who are long-time SCCA racers. Randy Pobst races with a team of folks I know well, James Clay from Bimmerworld races with another, so yes, there are even professional racers who dip into Lemons and Chump.
But, they'll be the first to tell you that LeMons is a far cry from competitive wheel to wheel racing. Sure, there is a lot of passing in LeMons, but not passing for the lead on the same lap nor between cars of equal capabilities. Penalty laps, team penalties, judges, sharks strapped to the roof, Toyota minivans under airplane skins, all of that leads to an atmosphere that is more about having fun and lapping on track than racing.
The half of Chump/Lemons that are experienced with real W2W racing have places to race now - SCCA, NASA, Midwest Council, etc. So, back to specifics about your Hooptie 500 series:
*What about the SCCA/NASA/Council (or other established race club) does your intended demographic not care for?
*What are the race licensing requirements to drive in "Hooptie 500"?
*What are the safety rules with respect to cage design?
*What sort of cars are envisioned to be the class staples?