I'm not sure why the Accessibility Service for Norton 360 does not get set by default during installation. It is possible that Android does not permit an app to change that setting for security reasons?????
If the intrusive actions you are referring to are those listed in your image from the first post, those are not Norton requests. That is being presented as suggested Accessibility services by Android OS. They are just suggestions. Nothing that would be activated by starting the Norton 360 service.
Did you clear that message and try what it said to do? It looks like the Norton 360 app may be listed under the message. So what it is telling you to do is to tap on the Norton 360 app in the Accessibility Services section and turn on the 360 service.