The way I see it, this community should be a welcoming community. We should be accepting of other users, regardless of race, sex, sexual orientation, gender identity, and a whole bunch of factors that are too numerous to enumerate in full here. In particular, we should not make posts that make certain classes of people uncomfortable.
In particular, if, say, Zoe Quinn were to make an account here and post, she should be respected like any other poster. It's OK to criticize her ideas, but we should not be making personal attacks on her. Similarly, it is OK to criticize the Feminist Frequency videos (but make sure you at least watch the video or read the transcript), but it is not OK to make personal attacks on the maker of those videos.
Also, there are some terms that, simply put, are offensive and should not be used. (Note, however, the use-mention distinction; It is OK to mention the words as long as you don't actually invoke the meaning of said words.)
Another thing: Downrating should only be done to posts that detract from the conversation, are offensive, or are otherwise problematic. In particular, disagreement with the context of the post is not a good enough reason to click the "-" button.