"You don't need to use Breitbart. It won't help. And I wonder about the good faith of people who start these threads - I strongly suspect that at least in some cases (don't know about this particular OP) they are agents provocateurs trying to get screenshots to "prove" that MN feminists are in fact far right nuts."
Well if that was my intention, it would be a guilt by association fallacy. So as a tactic... well it would have limited value because anyone could just point out that it's a fallacy.
Having a certain agreement with one point in one particular article, doesn't mean you agree with everything ever published by Breitbart. In fact, you may still very largely disagree with it.
As for worries that people will make accusations of "extremism" if you read/link a Breitbart article, yes sure, some people will certainly think / accuse you of that. But then, these days, you only need to deny that men are women and you are already considered a "far right extremist"; the bar isn't that high these days!
For myself, I have read some of their (Breitbart) articles, and the content doesn't appear any more "extreme" to me than Fox News punditry. It's not anti-semitic conspiracy theories or white supremacy.
As for "bias", as I went into before, if you have an open bias then it's fine to give political punditry from only one side. That isn't bad journalism in itself. I would be far more concerned about the issue of bias in the mainstream media.
And although political bias can result in errors in stories, (so e.g. you ignore things that are inconvenient to the narrative you want to push), it's maybe worth pointing out that "bias" by itself doesn't count against a story. You can be heavily biased and completely correct about a story. If a left-wing paper accuses a right-wing politician of corruption, of course they may well have an agenda in play beyond just the noble cause of wanting clean politics, but that doesn't tell you whether the story is correct or not.