Thanks to the power options available on virtually any type of RV now, setting them up can be as easy as you're willing to spend on options for. Setting up my 5er involves pushing a button to level, and another button to get it ready to hook the truck up to it when leaving It goes back to the height it was at when I disconnected. Backup cameras on the truck make backing into the hitch a breeze, and the camera on the back of the 5er makes getting into the spot easy. Even the power cord is on a powered reel, so you don't have to deal with winding up the cord. The stinky slinky and water hose are the same as everyone has to deal with, which could be an issue if you have arthritic hands. I didn't get power steps and don't find that to be a problem at this time, but could easily add them should I ever need to.
I can't imagine many trips where you don't need transportation at your destination, so towing a toad, or having a tow vehicle are a necessity in my book. Either way, connecting and disconnecting should be quick and painless depending on the setup you choose.
As to whether a car or truck is easier to get in and out of, Being a large guy I prefer trucks as it's easier for me to step up rather than sitting down, and when my back is acting up I find it difficult to pull my leg in enough to get them in a car door. Being 6'3 is part of the problem there, but the wife also finds it easier to get in the truck than either of our cars when her hip is acting up. I think it depends on how you set up the steps, grab handles etc and what sort of mobility issues you have. For general running around though, I often prefer a car as a full size truck is more difficult to maneuver in some areas. In the end I can easily make do with either type vehicle, and will at times wish I had the other type no matter what I'm using.
In the end, while handicaps may become an issue in what works best for you, most should be easy to overcome. It will probably just be a matter of preference just like it was when you were young and hopefully healthy.
