Do you have worked out numbers (in terms of community participation, support dollars, increased real-world violence, etc.) comparing the effect of having the censorship policy and the effect of allowing discussions that would be censored by the proposed policy? The request for "Consequences we haven't considered" is hard to meet until we know with sufficient detail what exactly you have considered.

My gut thinks it is unlikely that having a censorship policy has a smaller negative public relations effect than having occasional discussions that violate the proposed policy. I know that I am personally much less okay with the proposed censorship policy than with having occasional posts and comments on LW that would violate the proposed policy.