I put "keep your negative commentary to yourself" but that was really hypocritical of me, considering how negative I can sometimes be. I think both links and comments are always good, generally speaking. When saying negative stuff, well, sometimes I will lock my posts as you have seen. As for what others do? I would hope they do what they feel comfortable doing. I suppose I would rather people speak up and let me know if something I have written bothers them or makes them uncomfortable, so, therefore I should theoretically play by the same rules.

With fanfic and vids and such, I usually do try to comment if I liked it, since comments mean a lot to me, even if it's only a couple of words.