how in the heck to pick a used class A

I feel the same about slideouts. Don't need 'em, and they're another place to leak. The sway bar could be from driving fast or over rough terrain and the differential could be from driving on sand or snow or even from towing. So at 60,000, and 17 years it's noteworthy but not worrisome. Glad to hear it still has life. That was worrisome. Like you I expect to use it lightly. Where were the leaks? That could be systemic and something I should look closely for. Also where did you find the rattling? I too am not a mechanic, but I have a lot of experience trouble-shooting issues and taking care of the small ones on yachts. Many of the systems are very similar. The '99 has the Ford V-10 package I believe. The one I'm looking at has the GM 454 Workhorse. I hear the V-10 is known for blowing out spark plugs, but it's also known for doing 250,000 miles + with relatively few problems. The GM Workhorse is known for burning up plug wires and poor gas mileage (read one guy talking about 3.5 mpg). Both are supposedly fixable, The V-10 by adding helicoil sleeves and the GM by cooling the motor. I haven't been able to find talk on how far the GM 454 7.4L will run nor repairs expected.