Hi Gundog.
My TPO documents said to use Murphy’s Oil Soap to clean. We have mildew issues in Fl so I add 1/3 C bleach to the bucket.
I would re-ask your two questions in the appropriate forums for better response.
I would also scour Youtube for vids.
I would leave the existing lap sealant and use Eternabond on the end caps and vents.
My Expy has been stored outside it’s life and I would leave the roof to wall seal alone if it looks good. I just had mine inspected and resealed and they said it’s fine; cause more headaches if you mess with it.
The fuel filters need refilled before installing but you need to use pre filtered fuel. You can also thread a threaded nipple into the center hole and fill the filter thru the side holes. Fleetwood also sells a primer pump that bolts to the fuel filter mount.
Transcynd trans fluid is $70/gal unless there is a generic. Check to see when’s it’s due and if he used ext life. Last time I checked it’s pricey.