Sometimes great deals like this come along and all it takes is a little leg work to take advantage of the opportunity.
After cleaning, the first thing I would do is change the outside appearance. If it was a drug den then who knows how many people were in and out of it, and if they recognize it then they may want to come back to it again. $20 in cheap spray paint can do wonders for temporarily changing the appearance.
Then I’d make sure the roof, walls, and flooring are sturdy with no mold or mildew in the RV.
After that, I would want to convert it into a mobile command center. A bug out trailer of sorts. Clean the fresh water tank and double check the entire water system to ensure it all works as it should. If it doesn’t then go around to RV dealers to the parts counter to see if they have any water tanks laying around that someone ordered but never picked up. My dad did this and found a brand new 40 gallon fresh water tank. The dealership sold it to him for $40 just to get it out of their warehouse. It will be extremely hazardous but you should make sure the black tank is cleaned out too.
Next I’d look into solar for the roof and some kind of battery storage. If you are going to be using a lot of batteries, with the exception of lithium batteries, I would try to find a place to mount them as close to the axle as possible. Batteries can add a LOT of weight very fast.
Wire up 12 volt cameras all around the RV. You can buy aftermarket vehicle backup cameras for pretty cheap. Get a 12 volt monitor and a video switching box and you will easily be able to check the perimeter of the RV without ever looking out of a window.
Then there’s the things that would make life easier. Sleeping quarters, a stocked kitchen, and some place to sit down on.
Just a few ideas from my crazy mind!
Prepare for the worst, hope for the best