When it comes to any kind of motor home, there is a delicate balance between "excess weight capability" and "quality of ride" which sometimes can influence "handling". Generally speaking, the more excess weight capability, the more harsh the ride will be, and the better it will handle. Less excess capability makes a softer ride, but might handle worse. An empty heavy duty van or pick-up truck, the harsh ride exists too, but you are not driving a house. There is a huge difference shaking up a house and it's contents, versus an empty heavy duty van or pickup.
In my experience, to avoid shaking everything to death, you need minimal extra load capability applied to both axles, and then deal with any handling issues with heavy duty suspension upgrades. How much is considered minimal extra margin? I can't say. I can say that my rig loaded heavy during a vacation has roughly 200 pounds extra weight margin on the rear axle, and most recently has been reduced to 500 pounds on the front axle. My rig is tail heavy so it is what it is. My front axle once had so much extra weight margin until I replaced the stock front coil springs with lower spring weighted ones. Changed just recently, the softer ride up front has been a real pleasure. I should have made that change many years ago.
You can read about my front coil spring project with pictures by
CLICKING HERE.