Great place for rebuilding advice and feedback. I looked at your photos. Ours is a 2003 22 foot Itasca Spirit. I used roof tape on most of the seams up top and on the sides. Also sealed all the openings for lights etc to prevent leaks. Our had overhead leak stains when we bought it but I have not ever seen an active leak. When we lived in AZ and did the taping there was not much rain.
I have an old converter and I lose batteries on a regular basis. I have just lived with it.
We have not been out in our RV since March. It was that kind of year. I read rv.net before I bought and after I joined for several years. I totally enjoy the sharing by people here and their help and opinions. Good Luck!