Hoosier Welcome
I have traveled the country for years. A little common sense and some situational awareness goes a long way to keeping you safe. I've meet a bunch of great people on the road and only a couple of dirt bags but they were easy to spot. If it does not feel right, leave, don't stop.
As for renting, the insurance probably has a lot to do with more class C's being rented than travel trailers (TT's). The only TT's I've seen rented are small light pop ups. I have seen larger TT's for rent on the internet. Also if you rent a van there may be a no towing clause. Since there are so many different TT's and they require a specific weight distribution hitch many van rental companies will just say no. Towing opens liabilities that most rental places won't want to deal with. For what you'd renting a class C for the month you could buy a used TT. Last I remember it was $750-850 a week plus mileage (some are like $0.32 per mile over 200 miles per day). In realty for what 2 month would cost you it would be cheaper to buy a used trailer for cash. Lots of good deals probably find a sweat one for under $4,000. Heck you can get a nice TT new for less than $200 a month in payments if you wanted. Don't know that much about the price of used class C's but for what the rental is you could buy or put a nice down payment on a nice used rig.
PS: If you look at new, don't worry too much about MSRP. Haggle and you can do ok. I go mine for 70% of MSRP so don't let that scare you. If our local dealer won't haggle you can buy on line and have it shipped to you. Point is, there are options.