I agree about getting insurance. It's like any insurance, in that if you buy it and don't need it, it's money spent that you didn't need to spend. But if you end up needing the insurance, it can save you a lot of otherwise lost money.
I sailed with Viking River Cruises a couple of years ago in France, and had a great time. It's not the same experience as mega-ship cruising, and has a lot of advantages. The company did a good job for us.