Docker can be run rootless. Podman is rootless by default.
I build certain containers from scratch. Very popular FOSS software can be trusted, but if you’re as paranoid, you should probably run the bare-minimum software in the first-place.
It’s a mess if you’re not used to it. But yes, normal unix networking is somewhat simpler (like someone mentioned, LXC containers can be a decent idea). Well, you’ll realise that Docker is not really top-dog in terms of complexity when you start playing with the big boys like full-fledged k8s