I think we should have a convention for this and that we should try to implement both of your suggestions.
The first one being there for purely conventional reasons and for the regulars... However, using '#' might not be most suitable because it could also indicate a commented line in a bash
piece of code.
The second one for new people, accompanied with a link (run this as root) to a google search or another question that addresses running stuff as root.
update: I created a questionquestion that you can link to for this purpose.