I can't speak for getting an RV into South America, but folks who think the whole continent is a morass of crime are just plain ignorant.
I've spent time in Bolivia, in Ecuador, and in Peru (a lot there). These folks are among the friendliest you'll meet anywhere. Sure, there's a criminal element, but to me it is less evident than in US urban areas.
They have a great culture they are proud of, good food, and some wonderful sites to visit. I ate the best steak of my life in Bolivia for $3 with all the trimmings. Tourists and visitors are extended courtesy everywhere.
Interestingly, most of the people don't much care for the folks in their neighboring countries. And democracy is an ongoing project in a lot of places. None of that affects a visitor -- go on down and enjoy it!