Magilla,
Well Sir, I've done exactly what you're thinking of. We had a '99 Fleetwood Bounder 34V with the F-53 chassis and the V-10. That rig had a 13' overhang from the vertical centerline of the rear wheels. I built the rack which, I tied into the factory hitch and, I had two other recievers, one on each side that were used as auxiliary weight carrying assistants and, also stabilization.
The rack was built with a receiver added to it. We hauled a Yamaha TW 200 on it and, towed our '04 Jeep Rubicon too. That rack didn't even flex any with the weight of the bike on it. The rear axle of that Bounder was I think, a 10,000 lb. rear axle. I was close but, not over the limits with the bike on the back.
My intent was to haul my XR 650L which, was right at 150 lbs. more than the TW but, never did. It would have handled that bike easily too. But, one of the main problems with carrying a heavier bike on a rack like that is, loading and un loading SAFELY! Because the height of the rack, can present a problem as you're loading.
So, you'll have to determine what will allow you to do things safely and easily. Yes, your bike will get a bit dirty back there but, nothing that a quick sprits can't take care of.
We carried our '08 Honda Goldwing Gl1800 on the back of our present rig, an '04 Itasca Horizon with the C-7 CAT 330HP and, there was no damage to the paint what so ever. Yep, it got dirty, no doubt about that but, a quick rinse was in order and all was well. I tried a cover and, that sucked. But, I used a lift on a bike that size.
You won't need and, already know that one won't work for your situations. Good luck.
Scott