smilano -
I believe the window warranty is parts and labor for the first 2 years and parts only for the third year, so you are out of luck there. We have had several windows repaired at
Suncoast Designers in Florida, and we have 2 more to do again this year. They charge $200 to $250 per window, and you can take the windows out and ship them or you can drive your RV there (they have free hookups to stay overnight). The price is the same. There are other places that do the repairs (one in Elkhart and one in Arkansas), but I can't remember the names and I don't know their prices.
Call Tiffin about the wet bay floor repair. I don't know how long they cover that repair. They have several places around the country to do those repairs, but it is probably easiest to go to Red Bay since it sounds like you will be full-timers. The repairs can usually be done in one day, but figure on spending up to a week in Red Bay waiting to get in depending on what time of you go (spring and fall are busiest because of snowbirds).
The other well-known problem Tiffin has had is cracks in the radii along the edges of the roof. This problem started around 2007, which is when Tiffin started using one-piece fiberglass roofs. The roof was previously flat fiberglass on the top with radiused aluminum rails along the edges. Make sure the inspector climbs up on the roof to see if the motorhome has a one-piece roof, and if it does, have him check the edge radii for cracks. Cracks usually appear first in areas that are painted black. If the radii are separate rails, it is likely they have already been replaced.
Good luck, and let us know how the inspection goes and what you decide.