Three things that are paramount in my mind in order to avoid future, catastrophic issue:
1. Roof edge sealing - Winnebago roofs are surfaced by a thin, fiberglass material called Filon. The edges are inserted into an aluminum extrusion and kept in place with adhesive caulking. Failure of this adhesive can result in catastrophic failure with the roof covering literally blowing off. There are numerous posts on Winnieowners on how to deal with this.
2. Windshield sealing - Winnebago windshield seals can leak and cause rusting of the metal frame. Again, there are numerous posts on Winnieowners on this issue.
3. Leaks of any kind can also be catastrophic over time so make sure all roof penetrations, vents, etc. are properly sealed. Many of us use Eternabond tape for this. There are debates about this but it's effective, easy to use and lasts a long time. Again there are many threads on Winnieowners about this.
Winnebago owners are fortunate in that Winnebago provides a wealth of technical information online about their motorhomes, including electrical and plumbing diagrams, illustrated parts manuals, etc. There are also a number of "Service Tips" that explain routine service items. They also provide what are known as "Call Out Sheets" that document the various caulkings and sealants used on our MHs. Although these are published by year/model, this is an evolving issue and the info for more recent years can give you more timely info:
https://www.winnebago.com/owners/owner-resources
Good luck.