The graying is discolored clear coat that is common in that year Beavers cabinet finish. The cabinets should be mounted to the structural framing, so I don't see how the spots could be mounting points. The crack in the fiberglass will just get bigger.
The wavy roof line is something I would run away from, as I suspect it is water damage. Regardless...it should be straight. The roof is covered by s single sheet of fiberglass front to rear and side to side. That was a very well built coach when it was new and from what you describe it seems to have succumbed to the rain and too much sun. While these things do not make it a bad buy, they would impact the purchase a lot. Below low NADA by a lot. There are many, many coaches out there. Find a better one.
Full time since Nov 2012 RVM#41 Gary and Marian Hill 2001 Monaco Dynasty Jack 38' 370 hp ....If it ain't broke I can still fix it.
Like putting shoes on an octopuss, so are the days of our lives....