My ags was 141 bucks and two wires on the generator. Pretty easy.
DVD is dead art. There is almost no reasonable reason to have a DVD player other than to salvage a past investment in a dead technology. It's like installing a cassette player to salvage a collection.
Download amazon and netflix movies on your phone or on a cast off outdated phone you'll use just for movies.
Roku plugs into any TV with a USB port, some are hdmi. Any TV in any modern rv will have USB and hdmi ports. Install seperate rokus on each TV. They're about 19 bucks to 60 bucks each. The 19 buck roku units work just fine and are the size of a thumb drive. Cables are outdated technology. No sense in running them everywhere to save 6 bucks net.
Dimmers are cheap and easy to install.
Dash fans? They make afertmarket clip on fans that run off of USB.
https://www.amazon.com/s?k=USB+fan&ref=is_s
I don't know about the paint.