I think there are two directions in which some thinking, compressing and rewriting can make this essay stronger.

First, you are concentrated on the aspect of anonymity that is about speaking. That is, you are considering the consequences of expressing oneself either with or without one's "true" identity at stake. As I have mentioned in other writing from time to time, it is at least as important, perhaps more important, to consider the aspect of anonymity that is about reading. We are aware that we believe in freedom of speech, because our constitutional language tells us so. But we also believe in freedom of thought---which the 18th century language mostly treats in the context of religious thought---and freedom of thought requires that our reading not be tracked, associated with us, potentially drawing negative social consequences. Unless we can read without putting our identity at stake, there is no freedom of thought. So who needs anonymity to read? And who has managed---whatever may be said about trolling, bullying and the like---to give a justifcation for destroying the anonymity of reading that anyone can believe in?

Second, within your current focus on speaking or expression, what are the distinctions between anonymity and pseudonymity for your analysis? Associating an identity with public expression allows for continuity or persistence: Publius can issue more than one Federalist paper. The Letter to a Dissenter, on the other hand, needed no authorial fiction to hold it up: only the words themselves mattered. Surely Mark Twain (or should I say Samuel Clemens?) was right when he said that Shakespeare's plays were either written by Shakespeare or by someone else using his name.

The right claimed by the use of anonymity is that said by Brandeis and Warren to be the one most valued by civilized men: the right to be let alone. It might be productive inquire about the relation the Net imposes on us with respect to identity whether the purpose is to prevent aloneness altogether.