Sticks and staples do not a good RV make!!
I couldn't have said it better...
J Patroni, you can build an RV for me anytime. Unfortunately, you wouldn't be able to compete in the marketplace with high build quality since most units never leave asphalt so the shortcomings never materialize for the owners. To the good, there are a few manufacturers building solid units, but they are rare and pricey. Using a welded frame or a monocoque layup to carry structural and dynamic loads is the only way to build an RV IMO, as your experience with the foam shows.
If anyone's looking for a laugh, check out the 'Motorhome Racing' episode of Top Gear. It's online...and it's a hoot.
Some beefy RVs: