Little or no mechanical knowledge or capability

You are going to have to learn how to do some basic things for yourself. I can't imagine for example you will hire someone to drain and fill your tanks. Some RV's winterizing is just as easy. When you shop for a RV ask about basic maintenance and what is involved some are easier to work on then others. Find the one that works for you. I am not saying you need to do all your own work but something as simple as how the drains for your tanks are set up can make a difference in your ability to do it.