All of the examples you mention are good ones, although I think there are some valid blanket prohibitions too. For example, writers should never engage in cultural appropriation. That happens when writers don’t do the necessary research and rely on stereotypes instead. As long as the writer is respectful, s/he can write anything. But when arrogance and entitlement get involved (and they’re present in everyone’s psyche), it’s possible for writers to create some truly offensive work.