Other posters covered water intrusion well. It is the worst enemy of an RV. If the renewal of suspect areas is due, plan on doing it.
Appliances should be verified in working order. They do have an expected life, dependent on usage. Absorption fridges are the most common failure with common life of 10 years. However if they have had steady use Ive seen them last over 40 years.
Seems like ocassional use shortens their life, so a lightly used camper may be in better condition with little wear, due to lack of use fridge, battery( storage without charge) may be suspect to need replacement soon. No other appliance has a ( life) but the cold water heater, that is dependent on service of its sacrificial anode, so little use is a plus.
Tires and suspension are a great indicator of use. If wear is even and light, that does not indicate a lightly used unit, it just means it hasnt gone far.
I do not fear chinese tires. Now 9 years on chen yung long march g14 245/85//16. rated 110 psi, running. 85psi. 45 k miles Wear and service is wonderful. Its about underusing capacity. When you stress your limits to capacity, tow or towed is when issues happen .
over truck , under load do your due diligence.
