I'm a bit baffled you listed germs as your first reason for not liking a cruise... is this a phobia?
I wasn't really making a list ordered by fear, but it's rare I'll wash my hands in a public restroom and then touch any door handles with my bare hands afterward. Kinda defeats the purpose of washing to start with.
And yeah, I'm a bit germophobic, however that is spelled. I'd never put food in a shopping cart seat, but see other people do it all of the time.
I don't have a huge fear of large ships, but that doesn't mean I wouldn't carry on some hand sanitizer. I'm conscious of a lot of things other people pay no attention to. I still come out of my basement now and then.
I'm not really a fan of how modern cruise ships are constructed so top-heavy, either. I'm not alone there.