I did the same once upon a time. Ultimately though, I decided that flagging them as annoying was a worse solution to just actively blocking them and never seeing anything else they post.

I think RES style tags would be great to implement, maybe even the up vote counter so you can track exactly how you’re engaging with a particular user’s content.

However as far as a web of trust goes, I’m not saying it can’t work, but a web of trust would require a substantial userbase trusting or distrusting eachother to work effectively. It really just depends on whether the userbase at large would actively engage with that system, which I don’t think it would but I’m also not representative of the userbase.

I also forsee some potential issues. Could highly trusted users become the next power users? Could pseudo “cliques” form depending on who trusts who? Could people be brigaded as untrustworthy, and receive whatever negative outcome that entails? What if you trusted someone years ago, later they come out with a lot of bad stuff, and that then reflects poorly on you? I know these are simply what-ifs, but these seem very possible to me with that kind of system.