I tend to agree with your approach and I tend to follow those sorts of principles myself. The major difference is around AO3 fics with the Share button disabled - I haven't come across this yet, but if I did and there was no context/guidance in the author notes, I'd probably still feel fine to share the links openly in fannish spaces. I'm not a hardliner about "don't post if you wouldn't be okay with it being on the NYT", but I do feel that fundamentally if I post something publicly, I can't then tell people they're morally obligated not to share the link with anyone else.