>>/53232/
Kinda like a forum OP? or reddit, but I'm not saying that in a mean or insulting way though since reddit does something similar to what you want It could work if it's niche enough.
>>/53235/
You just get volunteer mods and shit like cloudflare/basedflare to prevent that.
And just put a disclaimer that every poster is responsible for their own post and the website can't control what other people post. Just to wash your hands clean of what other people do in the site.