Never used ratings. I use my journal almost exclusively for fannish stuff - and by that, I mean, nearly all are just exchange letters. The few posts of discussion are not remotely NSFW whatsoever.
I post all my fics (I don't do art) on AO3 too, and its tagging system works for me. I lock anything that is potentially an issue - but for me I have more the trouble that some RL people might find my fanworks, and certain ones I've written could get me in trouble at my work. So I lock them just in case. The rest, I figure people can read the tags and a/ns and click the back button if they don't like it.
no subject
I post all my fics (I don't do art) on AO3 too, and its tagging system works for me. I lock anything that is potentially an issue - but for me I have more the trouble that some RL people might find my fanworks, and certain ones I've written could get me in trouble at my work. So I lock them just in case. The rest, I figure people can read the tags and a/ns and click the back button if they don't like it.