At the age of 61 I took an 11 month solo trip. I have a class C so if I feel uncomfortable I am self contained, as are you.
Trust your gut when choosing a camp spot. I always stopped by 6PM and later 5PM so I could get settled before dark. I started my trip in Nov so night came a lot earlier then than later in the trip. I traveled with 2 cats which would be no help for protection. I did put out at least 2 lawn chairs, placed 2 coffee cups on the picnic table when appropriate. Just the common sense you talk about.
I love your slogan and that's just what I did. I'd been thinking of taking such a trip for a long time, so I finally took it. I stopped when I felt the time was right but I miss it.
enjoy yourself and go for it.