First, its 5 years old, with a high price. New engine, well, that a selling point, not a price point, unless they are including a 3 year warrantee on the MH. With 7,000 miles on it, I would assume it was used for 2 years, for non-full timers.
In the end, You are the only one that has to be satisfied with the answers to the questions, but they must be asked, in my mind. Be it cars, trucks, houses, or RVs, they are all built by people, and people do make mistakes, and companies find it easer and cheaper to cover these mistakes up than to fix them.